Issue #22558: Add remaining doc links to source code for Python-coded modules.
Reformat header above separator line (added if missing) to a common format.
Patch by Yoni Lavi.
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index be6c28c..c5c092c 100644
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -4,6 +4,9 @@
.. module:: multiprocessing
:synopsis: Process-based parallelism.
+**Source code:** :source:`Lib/multiprocessing/`
+
+--------------
Introduction
------------