CI documentation and precommit / ci recommandation for sha pinning and cooldown

[BarbUk]

• Add documentation about updating precommit hooks
• Add a documentation about the current ci workflow
• Link the ci workflow

Description

Following #2377 (comment), this PR add some documentation
about the CI, pre-commit and how to update them with sha pinning and a cooldown.

How Has This Been Tested?

The documentation build with:

sphinx-build -W -b html docs docs/_build/html

Checklist:

• My code follows the code style of this project.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• I have added tests to cover my changes, and all the new and existing tests pass.