Add extra_css to spec family
diff --git a/man/cell_spec.Rd b/man/cell_spec.Rd
index 40966ca..d50b580 100644
--- a/man/cell_spec.Rd
+++ b/man/cell_spec.Rd
@@ -8,7 +8,7 @@
 cell_spec(x, format, bold = FALSE, italic = FALSE, monospace = FALSE,
   color = NULL, background = NULL, align = NULL, font_size = NULL,
   angle = NULL, tooltip = NULL, popover = NULL, link = NULL,
-  escape = TRUE, background_as_tile = TRUE,
+  extra_css = NULL, escape = TRUE, background_as_tile = TRUE,
   latex_background_in_cell = TRUE)
 
 text_spec(x, format, bold = FALSE, italic = FALSE, monospace = FALSE,
@@ -61,6 +61,8 @@
 \item{link}{A vector of strings for url links. Can be used together with
 tooltip and popover.}
 
+\item{extra_css}{Extra css text to be passed into the cell}
+
 \item{escape}{T/F value showing whether special characters should be escaped.}
 
 \item{background_as_tile}{T/F value indicating if you want to have round
diff --git a/man/column_spec.Rd b/man/column_spec.Rd
index bbbd3a4..c3f0e35 100644
--- a/man/column_spec.Rd
+++ b/man/column_spec.Rd
@@ -6,7 +6,7 @@
 \usage{
 column_spec(kable_input, column, width = NULL, bold = FALSE,
   italic = FALSE, monospace = FALSE, color = NULL, background = NULL,
-  border_left = FALSE, border_right = FALSE)
+  border_left = FALSE, border_right = FALSE, extra_css = NULL)
 }
 \arguments{
 \item{kable_input}{Output of \code{knitr::kable()} with \code{format} specified}
@@ -38,6 +38,9 @@
 \item{border_right}{A logical variable indicating whether there should be a
 border line on the right of the selected column. In HTML, you can also pass
 in a character string for the CSS of the border line}
+
+\item{extra_css}{Extra css text to be passed into the cells of the row. Note
+that it's not for the whole column but to each individual cells}
 }
 \description{
 This function allows users to select a column and then specify
diff --git a/man/row_spec.Rd b/man/row_spec.Rd
index 6b037ea..0338b13 100644
--- a/man/row_spec.Rd
+++ b/man/row_spec.Rd
@@ -6,7 +6,7 @@
 \usage{
 row_spec(kable_input, row, bold = FALSE, italic = FALSE,
   monospace = FALSE, color = NULL, background = NULL, align = NULL,
-  font_size = NULL, angle = NULL)
+  font_size = NULL, angle = NULL, extra_css)
 }
 \arguments{
 \item{kable_input}{Output of \code{knitr::kable()} with \code{format} specified}
@@ -38,6 +38,9 @@
 \code{x-large}, \code{xx-large}, \code{smaller}, \code{larger}, \code{initial} and \code{inherit}.}
 
 \item{angle}{0-360, degree that the text will rotate.}
+
+\item{extra_css}{Extra css text to be passed into the cells of the row. Note
+that it's not for the whole row.}
 }
 \description{
 This function allows users to select a row and then specify