Setup "deeprob-kit-docs" repository or "gh-pages" branch for automatically versioned documentation

[loreloc]

Setup a new repository deeprob-org/deeprob-kit-docs or the special branch gh-pages containing versioned documentation.
Refer to sphinx-multiversion for building versioned documentation.
In particular, refer to a fork of sphinx-multiversion supporting sphinx-apidoc and sphinx-autodoc.

Finally, setup a GitHub Action to automatically push new documentation versions when:

1. A push on main branch is made.
2. A new tag/release is pushed.

However, this can also be done using Travis CI.