Add an index.md and edit the title levels in the documentation.

[lola-masson]

Update title levels

Add an index.md and edit the title levels in the documentation.

Add note about branch

add index for TOC control and edit title in readme

Fix levels of titles in Readmes

Edit pipeline for specific branch

Update toc

Add title to index.md

Change order of sections

Remove branch spec in pipeline

typo in changelog

(cherry picked from commit 4de5c0ffd1b76cd5750378048451b546ba3b9227)