bpo-33641: Convert RFC references into links. (GH-7103)


85% of them are already links.
(cherry picked from commit 0a36ac1a09587735237c5978ebd046313922869c)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Doc/library/logging.rst b/Doc/library/logging.rst
index 9a54bf9..6b48d64 100644
--- a/Doc/library/logging.rst
+++ b/Doc/library/logging.rst
@@ -516,7 +516,7 @@
    initialized with a format string for the message as a whole, as well as a
    format string for the date/time portion of a message.  If no *fmt* is
    specified, ``'%(message)s'`` is used.  If no *datefmt* is specified, an
-   ISO8601-like (or RFC3339-like) date format is used. See the
+   ISO8601-like (or :rfc:`3339`-like) date format is used. See the
    :meth:`formatTime` documentation for more details.
 
    The *style* parameter can be one of '%', '{' or '$' and determines how