Backport source links from 3.x.
Existing links have been updated to use the new reST role. In some
files, I have also made cosmetic changes to the header.
diff --git a/Doc/library/htmllib.rst b/Doc/library/htmllib.rst
index 4e22b6f..f253d12 100644
--- a/Doc/library/htmllib.rst
+++ b/Doc/library/htmllib.rst
@@ -165,6 +165,9 @@
Python 3.0. The :term:`2to3` tool will automatically adapt imports when
converting your sources to 3.0.
+**Source code:** :source:`Lib/htmlentitydefs.py`
+
+--------------
This module defines three dictionaries, ``name2codepoint``, ``codepoint2name``,
and ``entitydefs``. ``entitydefs`` is used by the :mod:`htmllib` module to