Documentation does not build right now

[smartsammler]

Hello,

The documentation on master does not build when calling python setup.py build_sphinx as expected.

I think it would be good to have at least the API documentation also accessible as HTML.

I can provide a PR to build the docu if you like to. Do I have to be based on the master or dev branch?

I guess the differences between the README.md and the docs/index.rst result from the fact that the docu does not work atm. Maybe it makes sense to have only one of them in the long run, but the current Spinx configuration only supports ReST, so that one would have to use a README.rst for GitHub, too, if one wants to merge them.
If you wish to have only one, I can open a new issue for it.

[smartsammler]

Are you interested in having a pulbicly accessible version of the documentation (read the docs)?
This implies some modifications, but might be nice to have, especially because one can integrate it with Github to automatically build the documentation.
For now I created an example at https://ocelot-collab-docu.readthedocs.io/en/latest/, but I think that at least one core developer should be the administrator, too, if you do not want to set it up on your own.
For the changes to get this running I can create a PR for sure, but it also involves some configuration steps at readthedocs.io itself.