Add Sphinx Documentation

[sanssecours]

Description

It might make sense to extend the documentation from a basic readme to a more fully fledged documentation that uses Sphinx and Read the Docs. One advantage of that approach is that we can build documentation for different versions of the API. Ideally we would also add the Fast API documentation to this online documentation. One option to do that might be the Sphinx OpenAPI spec renderer.

Todo

• Add Sphinx documentation
• Add OpenAPI information to documentation
• Publish documentation on Read The Docs too