New section header style.
Fix up a few synopses.
diff --git a/Doc/lib/libthread.tex b/Doc/lib/libthread.tex
index 2e55b41..df87118 100644
--- a/Doc/lib/libthread.tex
+++ b/Doc/lib/libthread.tex
@@ -1,7 +1,8 @@
-\section{Built-in Module \module{thread}}
+\section{\module{thread} ---
+ Multiple threads of control.}
\declaremodule{builtin}{thread}
-\modulesynopsis{Create multiple threads of control within one namespace.}
+\modulesynopsis{Create multiple threads of control within one interpreter.}
This module provides low-level primitives for working with multiple