Add alternate line colouring to button map tables to better distinguish 
rows.  Also increase the width of three column button tables slightly.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22483 a1c6a512-1295-4272-9138-f99709370657
diff --git a/manual/preamble.tex b/manual/preamble.tex
index 0d0082e..ce5fee2 100644
--- a/manual/preamble.tex
+++ b/manual/preamble.tex
@@ -36,6 +36,8 @@
 
 \usepackage{optional}
 
+\usepackage[table]{xcolor}
+
 \input{platform/\platform.tex}
 \input{features.tex}
 
@@ -317,6 +319,7 @@
 % Main Unit Key  &  Remote Key  &  Description \\
 
 \newenvironment{btnmap}[2]{%
+  \rowcolors{1}{}{gray!30}
   \expandafter\let\expandafter\SavedEndTab\csname endtabular*\endcsname
   \expandafter\renewcommand\expandafter*\csname endtabular*\endcsname{%
     \bottomrule
@@ -328,7 +331,7 @@
   \center
   \opt{HAVEREMOTEKEYMAP}{
     % here is the table width defined for 3 columns
-    \tabularx{.9\textwidth}{>{\raggedright\arraybackslash}p{.2\textwidth}>{\raggedright\arraybackslash}p{.2\textwidth}X}\toprule 
+    \tabularx{.95\textwidth}{>{\raggedright\arraybackslash}p{.2\textwidth}>{\raggedright\arraybackslash}p{.2\textwidth}X}\toprule
   }
   \nopt{HAVEREMOTEKEYMAP}{
     % here is the table width defined for 2 columns