Typo: "descrition" --> "description"

Add reference to the documentation for the Python documentation markup.

Fixed up a couple of descriptions.

This closes SF bug #430627.

Doc/templates/module.tex

 % Template for a library manual section.
 % PLEASE REMOVE THE COMMENTS AFTER USING THE TEMPLATE
+%
+% Complete documentation on the extended LaTeX markup used for Python
+% documentation is available in ``Documenting Python'', which is part
+% of the standard documentation for Python.  It may be found online
+% at:
+%
+%     http://www.python.org/doc/current/doc/doc.html
 
 % ==== 0. ====
 % Copy this file to <mydir>/lib<mymodule>.tex, and edit that file
@@ -13,7 +20,7 @@
 % appropriate.
 
 \section{\module{spam} ---
-         Short descrition, for section title}
+         Short description, for section title and table of contents}
 
 % Choose one of these to specify the module module name.  If there's
 % an underscore in the name, use
@@ -31,9 +38,9 @@
 % Please use a name that has already been used whenever applicable.  If this
 % is omitted, no availability statement is produced or implied.
 %
-%   \platform{UNIX}
+%   \platform{Unix}
 
-% These apply to all modules:
+% These apply to all modules, and may be given more than once:
 
 \moduleauthor{name}{email}		% Author of the module code;
 					% omit if not known.