Update docs config and refresh sphinx-apidoc

[alejgh]

Closes #13

I have solved most of the warnings generated when creating the sphinx docs of the module.

There is one warning that could not be solved, and fixing it would take a considerable amount of time:

• Warning when creating the documentation of the listener module, since the flask app is running outside of the application context.

However, since this warning does not interfere with the generation of the module's docs, I think it is the best to leave it for now.