diff --git a/docs/bookdown_example/_book/01-cross-format.md b/docs/bookdown/01-cross-format.md
similarity index 100%
rename from docs/bookdown_example/_book/01-cross-format.md
rename to docs/bookdown/01-cross-format.md
diff --git a/docs/bookdown_example/_book/02-bootstrap_in_gitbook.md b/docs/bookdown/02-bootstrap_in_gitbook.md
similarity index 100%
rename from docs/bookdown_example/_book/02-bootstrap_in_gitbook.md
rename to docs/bookdown/02-bootstrap_in_gitbook.md
diff --git a/docs/bookdown_example/_book/bookdown_example.epub b/docs/bookdown/bookdown_example.epub
similarity index 78%
rename from docs/bookdown_example/_book/bookdown_example.epub
rename to docs/bookdown/bookdown_example.epub
index 4364f32..650f35e 100644
--- a/docs/bookdown_example/_book/bookdown_example.epub
+++ b/docs/bookdown/bookdown_example.epub
Binary files differ
diff --git a/docs/bookdown/bookdown_example.pdf b/docs/bookdown/bookdown_example.pdf
new file mode 100644
index 0000000..cc1ef8c
--- /dev/null
+++ b/docs/bookdown/bookdown_example.pdf
Binary files differ
diff --git a/docs/bookdown_example/_book/bookdown_example.tex b/docs/bookdown/bookdown_example.tex
similarity index 100%
rename from docs/bookdown_example/_book/bookdown_example.tex
rename to docs/bookdown/bookdown_example.tex
diff --git a/docs/bookdown_example/_book/cross-format-tables-in-bookdown.html b/docs/bookdown/cross-format-tables-in-bookdown.html
similarity index 100%
rename from docs/bookdown_example/_book/cross-format-tables-in-bookdown.html
rename to docs/bookdown/cross-format-tables-in-bookdown.html
diff --git a/docs/bookdown_example/_book/index.html b/docs/bookdown/index.html
similarity index 100%
rename from docs/bookdown_example/_book/index.html
rename to docs/bookdown/index.html
diff --git a/docs/bookdown_example/_book/index.md b/docs/bookdown/index.md
similarity index 100%
rename from docs/bookdown_example/_book/index.md
rename to docs/bookdown/index.md
diff --git a/docs/bookdown_example/_book/libs/bsTable-3.3.7/bootstrapTable.min.css b/docs/bookdown/libs/bsTable-3.3.7/bootstrapTable.min.css
similarity index 100%
rename from docs/bookdown_example/_book/libs/bsTable-3.3.7/bootstrapTable.min.css
rename to docs/bookdown/libs/bsTable-3.3.7/bootstrapTable.min.css
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/css/fontawesome/fontawesome-webfont.ttf b/docs/bookdown/libs/gitbook-2.6.7/css/fontawesome/fontawesome-webfont.ttf
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/css/fontawesome/fontawesome-webfont.ttf
rename to docs/bookdown/libs/gitbook-2.6.7/css/fontawesome/fontawesome-webfont.ttf
Binary files differ
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-bookdown.css b/docs/bookdown/libs/gitbook-2.6.7/css/plugin-bookdown.css
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-bookdown.css
rename to docs/bookdown/libs/gitbook-2.6.7/css/plugin-bookdown.css
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-fontsettings.css b/docs/bookdown/libs/gitbook-2.6.7/css/plugin-fontsettings.css
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-fontsettings.css
rename to docs/bookdown/libs/gitbook-2.6.7/css/plugin-fontsettings.css
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-highlight.css b/docs/bookdown/libs/gitbook-2.6.7/css/plugin-highlight.css
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-highlight.css
rename to docs/bookdown/libs/gitbook-2.6.7/css/plugin-highlight.css
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-search.css b/docs/bookdown/libs/gitbook-2.6.7/css/plugin-search.css
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/css/plugin-search.css
rename to docs/bookdown/libs/gitbook-2.6.7/css/plugin-search.css
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/css/style.css b/docs/bookdown/libs/gitbook-2.6.7/css/style.css
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/css/style.css
rename to docs/bookdown/libs/gitbook-2.6.7/css/style.css
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/js/app.min.js b/docs/bookdown/libs/gitbook-2.6.7/js/app.min.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/js/app.min.js
rename to docs/bookdown/libs/gitbook-2.6.7/js/app.min.js
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/js/jquery.highlight.js b/docs/bookdown/libs/gitbook-2.6.7/js/jquery.highlight.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/js/jquery.highlight.js
rename to docs/bookdown/libs/gitbook-2.6.7/js/jquery.highlight.js
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/js/lunr.js b/docs/bookdown/libs/gitbook-2.6.7/js/lunr.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/js/lunr.js
rename to docs/bookdown/libs/gitbook-2.6.7/js/lunr.js
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-bookdown.js b/docs/bookdown/libs/gitbook-2.6.7/js/plugin-bookdown.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-bookdown.js
rename to docs/bookdown/libs/gitbook-2.6.7/js/plugin-bookdown.js
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-fontsettings.js b/docs/bookdown/libs/gitbook-2.6.7/js/plugin-fontsettings.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-fontsettings.js
rename to docs/bookdown/libs/gitbook-2.6.7/js/plugin-fontsettings.js
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-search.js b/docs/bookdown/libs/gitbook-2.6.7/js/plugin-search.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-search.js
rename to docs/bookdown/libs/gitbook-2.6.7/js/plugin-search.js
diff --git a/docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-sharing.js b/docs/bookdown/libs/gitbook-2.6.7/js/plugin-sharing.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/gitbook-2.6.7/js/plugin-sharing.js
rename to docs/bookdown/libs/gitbook-2.6.7/js/plugin-sharing.js
diff --git a/docs/bookdown_example/_book/libs/jquery-2.2.3/jquery.min.js b/docs/bookdown/libs/jquery-2.2.3/jquery.min.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/jquery-2.2.3/jquery.min.js
rename to docs/bookdown/libs/jquery-2.2.3/jquery.min.js
diff --git a/docs/bookdown_example/_book/libs/kePrint-0.0.1/kePrint.js b/docs/bookdown/libs/kePrint-0.0.1/kePrint.js
similarity index 100%
rename from docs/bookdown_example/_book/libs/kePrint-0.0.1/kePrint.js
rename to docs/bookdown/libs/kePrint-0.0.1/kePrint.js
diff --git a/docs/bookdown_example/_book/search_index.json b/docs/bookdown/search_index.json
similarity index 100%
rename from docs/bookdown_example/_book/search_index.json
rename to docs/bookdown/search_index.json
diff --git a/docs/bookdown_example/_book/use-bootstrap-tables-in-gitbooks-epub.html b/docs/bookdown/use-bootstrap-tables-in-gitbooks-epub.html
similarity index 100%
rename from docs/bookdown_example/_book/use-bootstrap-tables-in-gitbooks-epub.html
rename to docs/bookdown/use-bootstrap-tables-in-gitbooks-epub.html
diff --git a/docs/bookdown_example/_book/bookdown_example.pdf b/docs/bookdown_example/_book/bookdown_example.pdf
deleted file mode 100644
index c8d8ca4..0000000
--- a/docs/bookdown_example/_book/bookdown_example.pdf
+++ /dev/null
Binary files differ
diff --git a/docs/bookdown_example/_book/style.css b/docs/bookdown_example/_book/style.css
deleted file mode 100644
index d063c94..0000000
--- a/docs/bookdown_example/_book/style.css
+++ /dev/null
@@ -1,14 +0,0 @@
-/*!
- * Bootstrap v3.3.7 (http://getbootstrap.com)
- * Copyright 2011-2018 Twitter, Inc.
- * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
- */
-
-/*!
- * Generated using the Bootstrap Customizer (<none>)
- * Config saved to config.json and <none>
- *//*!
- * Bootstrap v3.3.7 (http://getbootstrap.com)
- * Copyright 2011-2016 Twitter, Inc.
- * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
- *//*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */table{border-collapse:collapse;border-spacing:0}td,th{padding:0}*{-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box}*:before,*:after{-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box}table{background-color:transparent}caption{padding-top:8px;padding-bottom:8px;color:#777;text-align:left}th{text-align:left}.table{width:100%;max-width:100%;margin-bottom:20px}.table>thead>tr>th,.table>tbody>tr>th,.table>tfoot>tr>th,.table>thead>tr>td,.table>tbody>tr>td,.table>tfoot>tr>td{padding:8px;line-height:1.42857143;vertical-align:top;border-top:1px solid #ddd}.table>thead>tr>th{vertical-align:bottom;border-bottom:2px solid #ddd}.table>caption+thead>tr:first-child>th,.table>colgroup+thead>tr:first-child>th,.table>thead:first-child>tr:first-child>th,.table>caption+thead>tr:first-child>td,.table>colgroup+thead>tr:first-child>td,.table>thead:first-child>tr:first-child>td{border-top:0}.table>tbody+tbody{border-top:2px solid #ddd}.table .table{background-color:#fff}.table-condensed>thead>tr>th,.table-condensed>tbody>tr>th,.table-condensed>tfoot>tr>th,.table-condensed>thead>tr>td,.table-condensed>tbody>tr>td,.table-condensed>tfoot>tr>td{padding:5px}.table-bordered{border:1px solid #ddd}.table-bordered>thead>tr>th,.table-bordered>tbody>tr>th,.table-bordered>tfoot>tr>th,.table-bordered>thead>tr>td,.table-bordered>tbody>tr>td,.table-bordered>tfoot>tr>td{border:1px solid #ddd}.table-bordered>thead>tr>th,.table-bordered>thead>tr>td{border-bottom-width:2px}.table-striped>tbody>tr:nth-of-type(odd){background-color:#f9f9f9}.table-hover>tbody>tr:hover{background-color:#f5f5f5}table col[class*="col-"]{position:static;float:none;display:table-column}table td[class*="col-"],table th[class*="col-"]{position:static;float:none;display:table-cell}.table>thead>tr>td.active,.table>tbody>tr>td.active,.table>tfoot>tr>td.active,.table>thead>tr>th.active,.table>tbody>tr>th.active,.table>tfoot>tr>th.active,.table>thead>tr.active>td,.table>tbody>tr.active>td,.table>tfoot>tr.active>td,.table>thead>tr.active>th,.table>tbody>tr.active>th,.table>tfoot>tr.active>th{background-color:#f5f5f5}.table-hover>tbody>tr>td.active:hover,.table-hover>tbody>tr>th.active:hover,.table-hover>tbody>tr.active:hover>td,.table-hover>tbody>tr:hover>.active,.table-hover>tbody>tr.active:hover>th{background-color:#e8e8e8}.table>thead>tr>td.success,.table>tbody>tr>td.success,.table>tfoot>tr>td.success,.table>thead>tr>th.success,.table>tbody>tr>th.success,.table>tfoot>tr>th.success,.table>thead>tr.success>td,.table>tbody>tr.success>td,.table>tfoot>tr.success>td,.table>thead>tr.success>th,.table>tbody>tr.success>th,.table>tfoot>tr.success>th{background-color:#dff0d8}.table-hover>tbody>tr>td.success:hover,.table-hover>tbody>tr>th.success:hover,.table-hover>tbody>tr.success:hover>td,.table-hover>tbody>tr:hover>.success,.table-hover>tbody>tr.success:hover>th{background-color:#d0e9c6}.table>thead>tr>td.info,.table>tbody>tr>td.info,.table>tfoot>tr>td.info,.table>thead>tr>th.info,.table>tbody>tr>th.info,.table>tfoot>tr>th.info,.table>thead>tr.info>td,.table>tbody>tr.info>td,.table>tfoot>tr.info>td,.table>thead>tr.info>th,.table>tbody>tr.info>th,.table>tfoot>tr.info>th{background-color:#d9edf7}.table-hover>tbody>tr>td.info:hover,.table-hover>tbody>tr>th.info:hover,.table-hover>tbody>tr.info:hover>td,.table-hover>tbody>tr:hover>.info,.table-hover>tbody>tr.info:hover>th{background-color:#c4e3f3}.table>thead>tr>td.warning,.table>tbody>tr>td.warning,.table>tfoot>tr>td.warning,.table>thead>tr>th.warning,.table>tbody>tr>th.warning,.table>tfoot>tr>th.warning,.table>thead>tr.warning>td,.table>tbody>tr.warning>td,.table>tfoot>tr.warning>td,.table>thead>tr.warning>th,.table>tbody>tr.warning>th,.table>tfoot>tr.warning>th{background-color:#fcf8e3}.table-hover>tbody>tr>td.warning:hover,.table-hover>tbody>tr>th.warning:hover,.table-hover>tbody>tr.warning:hover>td,.table-hover>tbody>tr:hover>.warning,.table-hover>tbody>tr.warning:hover>th{background-color:#faf2cc}.table>thead>tr>td.danger,.table>tbody>tr>td.danger,.table>tfoot>tr>td.danger,.table>thead>tr>th.danger,.table>tbody>tr>th.danger,.table>tfoot>tr>th.danger,.table>thead>tr.danger>td,.table>tbody>tr.danger>td,.table>tfoot>tr.danger>td,.table>thead>tr.danger>th,.table>tbody>tr.danger>th,.table>tfoot>tr.danger>th{background-color:#f2dede}.table-hover>tbody>tr>td.danger:hover,.table-hover>tbody>tr>th.danger:hover,.table-hover>tbody>tr.danger:hover>td,.table-hover>tbody>tr:hover>.danger,.table-hover>tbody>tr.danger:hover>th{background-color:#ebcccc}.table-responsive{overflow-x:auto;min-height:0.01%}@media screen and (max-width:767px){.table-responsive{width:100%;margin-bottom:15px;overflow-y:hidden;-ms-overflow-style:-ms-autohiding-scrollbar;border:1px solid #ddd}.table-responsive>.table{margin-bottom:0}.table-responsive>.table>thead>tr>th,.table-responsive>.table>tbody>tr>th,.table-responsive>.table>tfoot>tr>th,.table-responsive>.table>thead>tr>td,.table-responsive>.table>tbody>tr>td,.table-responsive>.table>tfoot>tr>td{white-space:nowrap}.table-responsive>.table-bordered{border:0}.table-responsive>.table-bordered>thead>tr>th:first-child,.table-responsive>.table-bordered>tbody>tr>th:first-child,.table-responsive>.table-bordered>tfoot>tr>th:first-child,.table-responsive>.table-bordered>thead>tr>td:first-child,.table-responsive>.table-bordered>tbody>tr>td:first-child,.table-responsive>.table-bordered>tfoot>tr>td:first-child{border-left:0}.table-responsive>.table-bordered>thead>tr>th:last-child,.table-responsive>.table-bordered>tbody>tr>th:last-child,.table-responsive>.table-bordered>tfoot>tr>th:last-child,.table-responsive>.table-bordered>thead>tr>td:last-child,.table-responsive>.table-bordered>tbody>tr>td:last-child,.table-responsive>.table-bordered>tfoot>tr>td:last-child{border-right:0}.table-responsive>.table-bordered>tbody>tr:last-child>th,.table-responsive>.table-bordered>tfoot>tr:last-child>th,.table-responsive>.table-bordered>tbody>tr:last-child>td,.table-responsive>.table-bordered>tfoot>tr:last-child>td{border-bottom:0}}.tooltip{position:absolute;z-index:1070;display:block;font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-style:normal;font-weight:normal;letter-spacing:normal;line-break:auto;line-height:1.42857143;text-align:left;text-align:start;text-decoration:none;text-shadow:none;text-transform:none;white-space:normal;word-break:normal;word-spacing:normal;word-wrap:normal;font-size:12px;opacity:0;filter:alpha(opacity=0)}.tooltip.in{opacity:.9;filter:alpha(opacity=90)}.tooltip.top{margin-top:-3px;padding:5px 0}.tooltip.right{margin-left:3px;padding:0 5px}.tooltip.bottom{margin-top:3px;padding:5px 0}.tooltip.left{margin-left:-3px;padding:0 5px}.tooltip-inner{max-width:200px;padding:3px 8px;color:#fff;text-align:center;background-color:#000;border-radius:4px}.tooltip-arrow{position:absolute;width:0;height:0;border-color:transparent;border-style:solid}.tooltip.top .tooltip-arrow{bottom:0;left:50%;margin-left:-5px;border-width:5px 5px 0;border-top-color:#000}.tooltip.top-left .tooltip-arrow{bottom:0;right:5px;margin-bottom:-5px;border-width:5px 5px 0;border-top-color:#000}.tooltip.top-right .tooltip-arrow{bottom:0;left:5px;margin-bottom:-5px;border-width:5px 5px 0;border-top-color:#000}.tooltip.right .tooltip-arrow{top:50%;left:0;margin-top:-5px;border-width:5px 5px 5px 0;border-right-color:#000}.tooltip.left .tooltip-arrow{top:50%;right:0;margin-top:-5px;border-width:5px 0 5px 5px;border-left-color:#000}.tooltip.bottom .tooltip-arrow{top:0;left:50%;margin-left:-5px;border-width:0 5px 5px;border-bottom-color:#000}.tooltip.bottom-left .tooltip-arrow{top:0;right:5px;margin-top:-5px;border-width:0 5px 5px;border-bottom-color:#000}.tooltip.bottom-right .tooltip-arrow{top:0;left:5px;margin-top:-5px;border-width:0 5px 5px;border-bottom-color:#000}.popover{position:absolute;top:0;left:0;z-index:1060;display:none;max-width:276px;padding:1px;font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-style:normal;font-weight:normal;letter-spacing:normal;line-break:auto;line-height:1.42857143;text-align:left;text-align:start;text-decoration:none;text-shadow:none;text-transform:none;white-space:normal;word-break:normal;word-spacing:normal;word-wrap:normal;font-size:14px;background-color:#fff;-webkit-background-clip:padding-box;background-clip:padding-box;border:1px solid #ccc;border:1px solid rgba(0,0,0,0.2);border-radius:6px;-webkit-box-shadow:0 5px 10px rgba(0,0,0,0.2);box-shadow:0 5px 10px rgba(0,0,0,0.2)}.popover.top{margin-top:-10px}.popover.right{margin-left:10px}.popover.bottom{margin-top:10px}.popover.left{margin-left:-10px}.popover-title{margin:0;padding:8px 14px;font-size:14px;background-color:#f7f7f7;border-bottom:1px solid #ebebeb;border-radius:5px 5px 0 0}.popover-content{padding:9px 14px}.popover>.arrow,.popover>.arrow:after{position:absolute;display:block;width:0;height:0;border-color:transparent;border-style:solid}.popover>.arrow{border-width:11px}.popover>.arrow:after{border-width:10px;content:""}.popover.top>.arrow{left:50%;margin-left:-11px;border-bottom-width:0;border-top-color:#999;border-top-color:rgba(0,0,0,0.25);bottom:-11px}.popover.top>.arrow:after{content:" ";bottom:1px;margin-left:-10px;border-bottom-width:0;border-top-color:#fff}.popover.right>.arrow{top:50%;left:-11px;margin-top:-11px;border-left-width:0;border-right-color:#999;border-right-color:rgba(0,0,0,0.25)}.popover.right>.arrow:after{content:" ";left:1px;bottom:-10px;border-left-width:0;border-right-color:#fff}.popover.bottom>.arrow{left:50%;margin-left:-11px;border-top-width:0;border-bottom-color:#999;border-bottom-color:rgba(0,0,0,0.25);top:-11px}.popover.bottom>.arrow:after{content:" ";top:1px;margin-left:-10px;border-top-width:0;border-bottom-color:#fff}.popover.left>.arrow{top:50%;right:-11px;margin-top:-11px;border-right-width:0;border-left-color:#999;border-left-color:rgba(0,0,0,0.25)}.popover.left>.arrow:after{content:" ";right:1px;border-right-width:0;border-left-color:#fff;bottom:-10px}.clearfix:before,.clearfix:after{content:" ";display:table}.clearfix:after{clear:both}.center-block{display:block;margin-left:auto;margin-right:auto}.pull-right{float:right !important}.pull-left{float:left !important}.hide{display:none !important}.show{display:block !important}.invisible{visibility:hidden}.text-hide{font:0/0 a;color:transparent;text-shadow:none;background-color:transparent;border:0}.hidden{display:none !important}.affix{position:fixed}
\ No newline at end of file
diff --git a/docs/bookdown_example/_book/use-bootstrap-tables-in-gitbooks.html b/docs/bookdown_example/_book/use-bootstrap-tables-in-gitbooks.html
deleted file mode 100644
index b573e60..0000000
--- a/docs/bookdown_example/_book/use-bootstrap-tables-in-gitbooks.html
+++ /dev/null
@@ -1,361 +0,0 @@
-<!DOCTYPE html>
-<html >
-
-<head>
-
-  <meta charset="UTF-8">
-  <meta http-equiv="X-UA-Compatible" content="IE=edge">
-  <title>Using kableExtra in Bookdown Projects</title>
-  <meta name="description" content="This example provides documentations for using kableExtra to customize tables in bookdown projects.">
-  <meta name="generator" content="bookdown  and GitBook 2.6.7">
-
-  <meta property="og:title" content="Using kableExtra in Bookdown Projects" />
-  <meta property="og:type" content="book" />
-  
-  
-  <meta property="og:description" content="This example provides documentations for using kableExtra to customize tables in bookdown projects." />
-  
-
-  <meta name="twitter:card" content="summary" />
-  <meta name="twitter:title" content="Using kableExtra in Bookdown Projects" />
-  
-  <meta name="twitter:description" content="This example provides documentations for using kableExtra to customize tables in bookdown projects." />
-  
-
-<meta name="author" content="Hao Zhu">
-
-
-<meta name="date" content="2018-10-03">
-
-  <meta name="viewport" content="width=device-width, initial-scale=1">
-  <meta name="apple-mobile-web-app-capable" content="yes">
-  <meta name="apple-mobile-web-app-status-bar-style" content="black">
-  
-  
-<link rel="prev" href="cross-format-tables-in-bookdown.html">
-
-<script src="libs/jquery-2.2.3/jquery.min.js"></script>
-<link href="libs/gitbook-2.6.7/css/style.css" rel="stylesheet" />
-<link href="libs/gitbook-2.6.7/css/plugin-bookdown.css" rel="stylesheet" />
-<link href="libs/gitbook-2.6.7/css/plugin-highlight.css" rel="stylesheet" />
-<link href="libs/gitbook-2.6.7/css/plugin-search.css" rel="stylesheet" />
-<link href="libs/gitbook-2.6.7/css/plugin-fontsettings.css" rel="stylesheet" />
-
-
-
-
-
-
-
-<script src="libs/kePrint-0.0.1/kePrint.js"></script>
-<link href="libs/bsTable-3.3.7/bootstrapTable.min.css" rel="stylesheet" />
-
-
-<style type="text/css">
-a.sourceLine { display: inline-block; line-height: 1.25; }
-a.sourceLine { pointer-events: none; color: inherit; text-decoration: inherit; }
-a.sourceLine:empty { height: 1.2em; position: absolute; }
-.sourceCode { overflow: visible; }
-code.sourceCode { white-space: pre; position: relative; }
-div.sourceCode { margin: 1em 0; }
-pre.sourceCode { margin: 0; }
-@media screen {
-div.sourceCode { overflow: auto; }
-}
-@media print {
-code.sourceCode { white-space: pre-wrap; }
-a.sourceLine { text-indent: -1em; padding-left: 1em; }
-}
-pre.numberSource a.sourceLine
-  { position: relative; }
-pre.numberSource a.sourceLine:empty
-  { position: absolute; }
-pre.numberSource a.sourceLine::before
-  { content: attr(data-line-number);
-    position: absolute; left: -5em; text-align: right; vertical-align: baseline;
-    border: none; pointer-events: all;
-    -webkit-touch-callout: none; -webkit-user-select: none;
-    -khtml-user-select: none; -moz-user-select: none;
-    -ms-user-select: none; user-select: none;
-    padding: 0 4px; width: 4em;
-    color: #aaaaaa;
-  }
-pre.numberSource { margin-left: 3em; border-left: 1px solid #aaaaaa;  padding-left: 4px; }
-div.sourceCode
-  {  }
-@media screen {
-a.sourceLine::before { text-decoration: underline; }
-}
-code span.al { color: #ff0000; font-weight: bold; } /* Alert */
-code span.an { color: #60a0b0; font-weight: bold; font-style: italic; } /* Annotation */
-code span.at { color: #7d9029; } /* Attribute */
-code span.bn { color: #40a070; } /* BaseN */
-code span.bu { } /* BuiltIn */
-code span.cf { color: #007020; font-weight: bold; } /* ControlFlow */
-code span.ch { color: #4070a0; } /* Char */
-code span.cn { color: #880000; } /* Constant */
-code span.co { color: #60a0b0; font-style: italic; } /* Comment */
-code span.cv { color: #60a0b0; font-weight: bold; font-style: italic; } /* CommentVar */
-code span.do { color: #ba2121; font-style: italic; } /* Documentation */
-code span.dt { color: #902000; } /* DataType */
-code span.dv { color: #40a070; } /* DecVal */
-code span.er { color: #ff0000; font-weight: bold; } /* Error */
-code span.ex { } /* Extension */
-code span.fl { color: #40a070; } /* Float */
-code span.fu { color: #06287e; } /* Function */
-code span.im { } /* Import */
-code span.in { color: #60a0b0; font-weight: bold; font-style: italic; } /* Information */
-code span.kw { color: #007020; font-weight: bold; } /* Keyword */
-code span.op { color: #666666; } /* Operator */
-code span.ot { color: #007020; } /* Other */
-code span.pp { color: #bc7a00; } /* Preprocessor */
-code span.sc { color: #4070a0; } /* SpecialChar */
-code span.ss { color: #bb6688; } /* SpecialString */
-code span.st { color: #4070a0; } /* String */
-code span.va { color: #19177c; } /* Variable */
-code span.vs { color: #4070a0; } /* VerbatimString */
-code span.wa { color: #60a0b0; font-weight: bold; font-style: italic; } /* Warning */
-</style>
-
-<link rel="stylesheet" href="style.css" type="text/css" />
-</head>
-
-<body>
-
-
-
-  <div class="book without-animation with-summary font-size-2 font-family-1" data-basepath=".">
-
-    <div class="book-summary">
-      <nav role="navigation">
-
-<ul class="summary">
-<li class="chapter" data-level="1" data-path="index.html"><a href="index.html"><i class="fa fa-check"></i><b>1</b> Introduction</a></li>
-<li class="chapter" data-level="2" data-path="cross-format-tables-in-bookdown.html"><a href="cross-format-tables-in-bookdown.html"><i class="fa fa-check"></i><b>2</b> Cross-format Tables in Bookdown</a><ul>
-<li class="chapter" data-level="2.1" data-path="cross-format-tables-in-bookdown.html"><a href="cross-format-tables-in-bookdown.html#use-the-k-m-approach-instead-of-m-k"><i class="fa fa-check"></i><b>2.1</b> Use the “K-M” approach instead of “M-K”</a></li>
-<li class="chapter" data-level="2.2" data-path="cross-format-tables-in-bookdown.html"><a href="cross-format-tables-in-bookdown.html#prepare-your-tables-for-both-formats"><i class="fa fa-check"></i><b>2.2</b> Prepare Your Tables for Both Formats</a></li>
-</ul></li>
-<li class="chapter" data-level="3" data-path="use-bootstrap-tables-in-gitbooks.html"><a href="use-bootstrap-tables-in-gitbooks.html"><i class="fa fa-check"></i><b>3</b> Use Bootstrap Tables in gitbooks</a></li>
-</ul>
-
-      </nav>
-    </div>
-
-    <div class="book-body">
-      <div class="body-inner">
-        <div class="book-header" role="navigation">
-          <h1>
-            <i class="fa fa-circle-o-notch fa-spin"></i><a href="./">Using kableExtra in Bookdown Projects</a>
-          </h1>
-        </div>
-
-        <div class="page-wrapper" tabindex="-1" role="main">
-          <div class="page-inner">
-
-            <section class="normal" id="section-">
-<div id="use-bootstrap-tables-in-gitbooks" class="section level1">
-<h1><span class="header-section-number">Chapter 3</span> Use Bootstrap Tables in gitbooks</h1>
-<p>Most of <code>kableExtra</code> tricks will work in <code>bookdown</code> except those requires <a href="http://getbootstrap.com/"><code>bootstrap</code></a>. By default, <code>rmarkdown</code> won’t load <code>bootstrap</code> for you on gitbook as there are potential conflict.</p>
-<pre class="sourceCode r"><code class="sourceCode r"><span class="kw">library</span>(kableExtra)
-<span class="kw">options</span>(<span class="dt">kableExtra.html.bsTable =</span> T)
-
-mtcars[<span class="dv">1</span><span class="op">:</span><span class="dv">5</span>, <span class="dv">1</span><span class="op">:</span><span class="dv">5</span>] <span class="op">%&gt;%</span>
-<span class="st">  </span><span class="kw">kable</span>(<span class="dt">booktabs =</span> T) <span class="op">%&gt;%</span><span class="st"> </span>
-<span class="st">  </span><span class="kw">kable_styling</span>(
-    <span class="dt">bootstrap_options =</span> <span class="kw">c</span>(<span class="st">&quot;striped&quot;</span>, <span class="st">&quot;bordered&quot;</span>),
-    <span class="dt">latex_options =</span> <span class="kw">c</span>(<span class="st">&quot;striped&quot;</span>),
-    <span class="dt">full_width =</span> F
-  ) <span class="op">%&gt;%</span>
-<span class="st">  </span><span class="kw">column_spec</span>(<span class="dv">1</span>, <span class="dt">color =</span> <span class="st">&quot;red&quot;</span>) <span class="op">%&gt;%</span>
-<span class="st">  </span><span class="kw">add_header_above</span>(<span class="kw">c</span>(<span class="st">&quot; &quot;</span>, <span class="st">&quot;Group A&quot;</span> =<span class="st"> </span><span class="dv">2</span>, <span class="st">&quot;Group B&quot;</span> =<span class="st"> </span><span class="dv">3</span>))</code></pre>
-<table class="table table-striped table-bordered" style="width: auto !important; margin-left: auto; margin-right: auto;">
-<thead>
-<tr>
-<th style="border-bottom:hidden" colspan="1">
-</th>
-<th style="border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;text-align: center; " colspan="2">
-<div style="border-bottom: 1px solid #ddd; padding-bottom: 5px; ">
-Group A
-</div>
-</th>
-<th style="border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;text-align: center; " colspan="3">
-<div style="border-bottom: 1px solid #ddd; padding-bottom: 5px; ">
-Group B
-</div>
-</th>
-</tr>
-<tr>
-<th style="text-align:left;">
-</th>
-<th style="text-align:right;">
-mpg
-</th>
-<th style="text-align:right;">
-cyl
-</th>
-<th style="text-align:right;">
-disp
-</th>
-<th style="text-align:right;">
-hp
-</th>
-<th style="text-align:right;">
-drat
-</th>
-</tr>
-</thead>
-<tbody>
-<tr>
-<td style="text-align:left;color: red;">
-Mazda RX4
-</td>
-<td style="text-align:right;">
-21.0
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-160
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.90
-</td>
-</tr>
-<tr>
-<td style="text-align:left;color: red;">
-Mazda RX4 Wag
-</td>
-<td style="text-align:right;">
-21.0
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-160
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.90
-</td>
-</tr>
-<tr>
-<td style="text-align:left;color: red;">
-Datsun 710
-</td>
-<td style="text-align:right;">
-22.8
-</td>
-<td style="text-align:right;">
-4
-</td>
-<td style="text-align:right;">
-108
-</td>
-<td style="text-align:right;">
-93
-</td>
-<td style="text-align:right;">
-3.85
-</td>
-</tr>
-<tr>
-<td style="text-align:left;color: red;">
-Hornet 4 Drive
-</td>
-<td style="text-align:right;">
-21.4
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-258
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.08
-</td>
-</tr>
-<tr>
-<td style="text-align:left;color: red;">
-Hornet Sportabout
-</td>
-<td style="text-align:right;">
-18.7
-</td>
-<td style="text-align:right;">
-8
-</td>
-<td style="text-align:right;">
-360
-</td>
-<td style="text-align:right;">
-175
-</td>
-<td style="text-align:right;">
-3.15
-</td>
-</tr>
-</tbody>
-</table>
-
-</div>
-            </section>
-
-          </div>
-        </div>
-      </div>
-<a href="cross-format-tables-in-bookdown.html" class="navigation navigation-prev navigation-unique" aria-label="Previous page"><i class="fa fa-angle-left"></i></a>
-
-    </div>
-  </div>
-<script src="libs/gitbook-2.6.7/js/app.min.js"></script>
-<script src="libs/gitbook-2.6.7/js/lunr.js"></script>
-<script src="libs/gitbook-2.6.7/js/plugin-search.js"></script>
-<script src="libs/gitbook-2.6.7/js/plugin-sharing.js"></script>
-<script src="libs/gitbook-2.6.7/js/plugin-fontsettings.js"></script>
-<script src="libs/gitbook-2.6.7/js/plugin-bookdown.js"></script>
-<script src="libs/gitbook-2.6.7/js/jquery.highlight.js"></script>
-<script>
-gitbook.require(["gitbook"], function(gitbook) {
-gitbook.start({
-"sharing": {
-"github": false,
-"facebook": true,
-"twitter": true,
-"google": false,
-"linkedin": false,
-"weibo": false,
-"instapper": false,
-"vk": false,
-"all": ["facebook", "google", "twitter", "linkedin", "weibo", "instapaper"]
-},
-"fontsettings": {
-"theme": "white",
-"family": "sans",
-"size": 2
-},
-"edit": {
-"link": null,
-"text": null
-},
-"download": ["bookdown_example.pdf", "bookdown_example.epub"],
-"toc": {
-"collapse": "subsection"
-}
-});
-});
-</script>
-
-</body>
-
-</html>
diff --git a/docs/bookdown_example/_bookdown.yml b/docs/bookdown_example/_bookdown.yml
index a189c96..d6b79b4 100644
--- a/docs/bookdown_example/_bookdown.yml
+++ b/docs/bookdown_example/_bookdown.yml
@@ -1,6 +1,7 @@
 book_filename: "bookdown_example"
 delete_merged_file: true
 new_session: true
+output_dir: "../bookdown"
 language:
   ui:
     chapter_name: "Chapter "