Update to use the output names used by latex2html for the Python Reference

Manual; the old FrameMaker names no longer apply.

Doc/html/index.html

@@ -12,7 +12,7 @@
 
 <LI><A HREF="lib/lib.html">Library Reference</A> (keep this under your pillow)
 
-<LI><A HREF="ref/ref-1.html">Language Reference</A> (for language lawyers)
+<LI><A HREF="ref/ref.html">Language Reference</A> (for language lawyers)
 
 <LI><A HREF="ext/ext.html">Extending and Embedding</A> (tutorial for
 C/C++ programmers)