Publish documentation on github.io

[ezio-melotti]

By reading https://www.docslikecode.com/articles/github-pages-python-sphinx/ and https://docs.github.com/en/pages/getting-started-with-github-pages/changing-the-visibility-of-your-github-pages-site it seems it should be possible to build the docs and publish them on a private github.io page. We could set up a GitHub action that is auto-triggered when something is pushed to docs/, that builds the docs and publishes them.

There is also a docker container that can be pulled to build the docs, and perhaps some GitHub action that does that out of the box already. I've also considered building the PDF, but it needs over 1GB of latex dependencies to be built, so it might not be worth it to automate it.

[ezio-melotti]

The docs are now published at https://simoc.space/docs/user_guide/
We should automate this with a GitHub action.

[ezio-melotti]

See:

• Automate docs deployment for simoc #210
• Add a workflow to build/check/upload docs. #212