Add R highlighting from RStudio (plus other dependencies)

demo/kitchen-sink/docs/tex.tex

@@ -0,0 +1,20 @@
+The quadratic formula is $$-b \pm \sqrt{b^2 - 4ac} \over 2a$$
+\bye
+
+\makeatletter
+ \newcommand{\be}{%
+ \begingroup
+ % \setlength{\arraycolsep}{2pt}
+ \eqnarray%
+ \@ifstar{\nonumber}{}%
+  }
+  \newcommand{\ee}{\endeqnarray\endgroup}
+  \makeatother
+
+ \begin{equation}
+ x=\left\{ \begin{array}{cl}
+ 0 & \textrm{if }A=\ldots\\
+ 1 & \textrm{if }B=\ldots\\
+ x & \textrm{this runs with as much text as you like, but without an raggeright text
+.}\end{array}\right.
+ \end{equation}