Update documentation for new config file

[stefsmeets]

The documentation should be updated to reflect the config file after #189

It would be really nice if we can use the code to autogenerate the table, i.e. by setting adding the docstrings in the data and then using mkdocstrings

[nichollsh]

It's important that we update the documentation sooner rather than later, as with the new config format the documentation is mostly useless. We could consider updating it only statically for now, and revisiting the mkdocstrings afterwards.

Is the idea that we would add docstrings for each variable inside the _config Python files? Alongside the validation?

[stefsmeets]

Yeah, we should add docstrings to every class. It's a bit of busy work, but I don't think it will be so bad. Perhaps we can work together on this. I will set up the boilerplate for mkdocstrings and set up a template for the docs.

[nichollsh]

Sounds good! I am happy to fill in the documentation strings themselves, if you can set up some kind of mechanism for generating the documentation from the code.

[stefsmeets]

I made a little start in #217, I think I will have it ready later today.