GH-101616: Mention the Docs Discourse forum in the "reporting docs issues" (GH-101617)

Fixes #101616

Author: Mariatta

Doc/bugs.rst

@@ -19,6 +19,9 @@ If you find a bug in this documentation or would like to propose an improvement,
 please submit a bug report on the :ref:`tracker <using-the-tracker>`.  If you
 have a suggestion on how to fix it, include that as well.
 
+You can also open a discussion item on our
+`Documentation Discourse forum <https://discuss.python.org/c/documentation/26>`_.
+
 If you're short on time, you can also email documentation bug reports to
 [email protected] (behavioral bugs can be sent to [email protected]).
 'docs@' is a mailing list run by volunteers; your request will be noticed,