Move documentation to its own branch

[paarthenon]

Right now the documentation is pulled from the docs folder of 3.0. While this was convenient at first, it is sloppy.

• It confuses the documentation commits with the code commits
• It creates duplication when the project has two main lines of development (3.0 and 2.x).

Documentation can be moved to its own branch. Ideally the documentation itself is the result of some CI process. I believe github workflows are up to the task.