Tie the advanced manual to the engine version

[micheles]

Currently it is generated only for master and it is impossible to go back to old versions (unless one looks at github). It should be put in standard places (latest, stable, X.Y.Z) as the regular manual.

[raoanirudh]

The template we're using also has an option to add a button that allows users to switch between versions of the documentation: https://pydata-sphinx-theme.readthedocs.io/en/stable/user_guide/version-dropdown.html

[micheles]

@nastasi-oq, can we close this now?

[CatalinaYepes]

Currently, I see a static page with master and latest. I think it will be better to add the drop-down button with the corresponding engine version.

[CatalinaYepes]

Here is a screenshot of the drop-down button taken from pandas documentation @nastasi-oq

[nastasi-oq]

I'm working on this new feature and I will extend it to the "user manual" too. Take in account that after the next release the dropdown will be populated with just 2 items:

3.16 LTS
master (target 3.17)

and so on for the next not LTS releases

3.16 LTS
3.17
master (target 3.18)

...

The effort to produce previous advanced manual versions would not be negligible and if you need it it must be discussed because not already implemented for github actions.