update bookdowm doc
diff --git a/docs/bookdown/libs/gitbook-2.6.7/css/plugin-gitbook-table.css b/docs/bookdown/libs/gitbook-2.6.7/css/plugin-gitbook-table.css
new file mode 100644
index 0000000..7fba1b9
--- /dev/null
+++ b/docs/bookdown/libs/gitbook-2.6.7/css/plugin-gitbook-table.css
@@ -0,0 +1 @@
+.book .book-body .page-wrapper .page-inner section.normal table{display:table;width:100%;border-collapse:collapse;border-spacing:0;overflow:auto}.book .book-body .page-wrapper .page-inner section.normal table td,.book .book-body .page-wrapper .page-inner section.normal table th{padding:6px 13px;border:1px solid #ddd}.book .book-body .page-wrapper .page-inner section.normal table tr{background-color:#fff;border-top:1px solid #ccc}.book .book-body .page-wrapper .page-inner section.normal table tr:nth-child(2n){background-color:#f8f8f8}.book .book-body .page-wrapper .page-inner section.normal table th{font-weight:700}