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/runpy.rst b/Doc/library/runpy.rst
index 905c64b..31562fe 100644
--- a/Doc/library/runpy.rst
+++ b/Doc/library/runpy.rst
@@ -8,6 +8,10 @@
.. versionadded:: 2.5
+**Source code:** :source:`Lib/runpy.py`
+
+--------------
+
The :mod:`runpy` module is used to locate and run Python modules without
importing them first. Its main use is to implement the :option:`-m` command
line switch that allows scripts to be located using the Python module