New section header style.

Fix up a few synopses.
diff --git a/Doc/lib/libgrp.tex b/Doc/lib/libgrp.tex
index 986c831..b15128d 100644
--- a/Doc/lib/libgrp.tex
+++ b/Doc/lib/libgrp.tex
@@ -1,4 +1,5 @@
-\section{Built-in Module \module{grp}}
+\section{\module{grp} ---
+         The group database.}
 \declaremodule{builtin}{grp}