Automate docs deployment, document the process

[pawamoy]

Currently, new releases are pushed to PyPI through GitHub Actions, using the official pypa/gh-action-pypi-publish action. However documentation is still deployed from local environments. We would like to automate the deployment of documentation through GitHub Actions too, as it's usually what works best for teams of maintainers/contributors, allowing anyone to quickly release docs enhancements without setting up a local environment and without requiring specific privileges.

This is a follow-up of #814, which is a bit dated and only shows comments about Travis CI.

In the process of automating docs deployments, we should also document this process (as well as how new releases are published).

Related issues:

• Missing documentation on installing Mkdocs development version dependencies #3025

[humitos]

However documentation is still deployed from local environments. We would like to automate the deployment of documentation through GitHub Actions too

In case you are also considering using Read the Docs for this, I can help you with that. Let me know.

[pawamoy]

Thanks for offering your help @humitos, we'll definitely consider this interesting option 👍