[3.12] Add lightweight comments to conf.py and update docs readme (GH-126100) (#126135)

Add lightweight comments to conf.py and update docs readme (GH-126100)

* Update contributing contact info in readme

* Add lightweight comments to improve docs workflow understanding

* Apply code review suggestions from @hugovk



* Add code review suggestion from @AA-Turner



* Update Doc/conf.py



* Update Doc/conf.py



* Update Doc/conf.py



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(cherry picked from commit 9effa0ff06047f3d957bf37267742a98106581ff)

Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>