#11785: fix the :mod: references in email package submodule titles.
Also adds the TOC entry for headerregistry.
diff --git a/Doc/library/email.parser.rst b/Doc/library/email.parser.rst
index a0303a4..96fe444 100644
--- a/Doc/library/email.parser.rst
+++ b/Doc/library/email.parser.rst
@@ -1,5 +1,5 @@
-:mod:`email`: Parsing email messages
-------------------------------------
+:mod:`email.parser`: Parsing email messages
+-------------------------------------------
.. module:: email.parser
:synopsis: Parse flat text email messages to produce a message object structure.