API documentation on readthedocs

[razofz]

Thought about taking this in the latest pull request, but I think this is a more general discussion (and the pull request is pretty crowded as it is).

There are two points to discuss here:

1. Currently, we provide descriptions in both the api.rst file, as well as in the docstrings, for the classes included in the API docs page. I. e., redundant. I would say that if we don't have anything extra we want to write in the api page, we should remove the descriptions from the rst file and let the docstrings be automatically included. Then the same descriptions can be found both on the docs API page and through Python help/docs functions. What do you think?
2. In the API docs page, we currently show only a couple of classes (e. g. Assay, DataStore). We do this with the sphinx autoclass directive. There exists a directive automodule, where everything from a module will be included in the API page, including the classes already there. Do we want to showcase only a select part of the classes, or should we take a more comprehensive approache and include the full module documentations?

Aimed at @parashardhapola 🙂

[razofz]

(Wanted to label this with e. g. 'discussion' and 'documentation', but I don't seem to have those permissions)