remove add_header_left entirely
update rd files
improve package documentation based on @wibeasley's suggestion
diff --git a/R/kableExtra-package.R b/R/kableExtra-package.R
index b0674be..a690e84 100644
--- a/R/kableExtra-package.R
+++ b/R/kableExtra-package.R
@@ -1,5 +1,56 @@
#' kableExtra
#'
+#' @description When we are talking about table generators in R,
+#' [knitr](https://yihui.name/knitr/)'s `kable()` function wins lots of flavor
+#' by its ultimate simplicity. Unlike those powerful table rendering engines
+#' such as [`xtable`](https://CRAN.R-project.org/package=xtable), the philosophy
+#' behind [`knitr::kable()`](https://rdrr.io/cran/knitr/man/kable.html) is to
+#' make it easy for programmers to use. Just as it claimed in its
+#' function description, "this is a very simple table generator. It is simple
+#' by design. It is not intended to replace any other R packages for making
+#' tables. - Yihui".
+#'
+#' However, the ultimate simplicity of `kable()` also brought troubles to some
+#' of us, especially for new R users, who may not have a lot of experience on
+#' generating tables in R. It is not rare to see people including experienced
+#' users asking questions like how to center/left-align a table on Stack
+#' Overflow. Also, for me personally, I found myself repeatedly parsing CSS
+#' into `kable()` for some very simple features like striped lines. For LaTeX,
+#' it's even worse since I'm almost Stack Overflow dependent for LaTeX...
+#' That's why this package `kableExtra` was created.
+#'
+#' I hope with `kableExtra`, you can
+#' - Use default base `kable()` (Or a good alternative for markdown tables is
+#' `pander::pander()`) for all simple tables
+#' - Use `kable()` with `kableExtra` to generate 90 % of complex/advanced
+#' tables in either HTML or LaTeX
+#' - Only have to mess with raw HTML/LaTeX in the last 10% cases where
+#' `kableExtra` cannot solve the problem
+#'
+#' @section Features:
+#' **Pipable syntax:** `kableExtra` is NOT a table generating package. It is a
+#' package that can "add features" to a `kable` output using a syntax
+#' that every useR loves - the [pipe](http://r4ds.had.co.nz/pipes.html).
+#' We see similar approaches to deal with plots in packages like `ggvis` and
+#' `plotly`. There is no reason why we cannot use it with tables.
+#'
+#' **Unified functions for both HTML and PDF:** Most functionalities in
+#' `kableExtra` can work in both HTML and PDF. In fact, as long as you
+#' specifies format in `kable` (which can be set globally through option
+#' `knitr.table.format`), functions in this package will pick the right way
+#' to manipulate the table be themselves. As a result, if users want to left
+#' align the table, `kable_styling(kable(...), position = "left")` will work
+#' in both HTML and PDF.
+#'
+#' @note If you found a feature on the documentation site that is not available
+#' in the version of `kableExtra` you are using, try to install the pre-release
+#' version from github. You can do so by running
+#' `devtools::install_github("haozhu233/kableExtra")`.
+#'
+#' Also, note that This package can load required LaTeX package automatically in
+#' vanilla rmarkdown. For customized rmarkdown templates, it is recommended to
+#' load related LaTeX packages manually.
+#'
#' @importFrom stringr str_count str_split str_match str_detect str_match_all
#' str_extract str_replace_all str_trim str_extract_all str_sub
#' @importFrom xml2 read_xml xml_attr xml_has_attr xml_attr<- read_html