New section header style.

Fix up a few synopses.
diff --git a/Doc/lib/libarray.tex b/Doc/lib/libarray.tex
index 4c8b5f2..b36ee26 100644
--- a/Doc/lib/libarray.tex
+++ b/Doc/lib/libarray.tex
@@ -1,4 +1,5 @@
-\section{Built-in Module \module{array}}
+\section{\module{array} ---
+         Efficient arrays of uniformly typed numeric values.}
 \declaremodule{builtin}{array}
 
 \modulesynopsis{Efficient arrays of uniformly typed numeric values.}