Add note about ongoing work with the new Sphinx guides
Proposed contents for new Sphinx guides
=======================================
+.. note::
+
+ This work is in progress, see discussion on `this Sphinx
+ issue <https://github.com/sphinx-doc/sphinx/issues/9165>`_
+ and the pull requests linked at the end.
+
The two main objectives are:
- Contributing a good Sphinx tutorial for beginners.
