Add versioning to API Docs

[folmos-at-orange]

Description

Currently, we have only the latest version of the API Docs published. With the incoming Khiops V11, it will be necessary to host at least the docs of the latest version (11.x) and those of (10.x).

Questions/Ideas

• Alternatives:
  • There are not many packages available, the best seems to be: https://github.com/Holzhaus/sphinx-multiversion
    • It rebuilds for each version, since we depend on khiops-python-tutorial this is non practical.
    • Also the package is unmaintained.
  • Move the hosting to https://readthedocs.com. This service has versioning support.
  • Migrate to the PyData Sphinx Theme
  • A bit of html template "hacking"
• In any case we'll need a repo to store the html docs, so we can store all versions.
  • The API Docs CI would need to be repurporsed so it push to that repo.
  • The code to do the CI deployment would need to go to the new repo.
• I'd store only latest version for each minor series. This is a good compromise between completeness and simplicity.