Both the end-user and developer documentation is combined into a single sphinx build (the two were previously split between github pages and sphinx).
To build the documentation, simply run
tox -e docs in the project root.
Serving the docs through http can be achieved by subsequently running
(cd docs/_build/html; python -m SimpleHTTPServer 8080) and accessing them
Many of the folders in the project have a README.rst which describes the purpose of the contents in that folder. These files are automatically included when building the documentation, through use of the include directive.
Include files for the providers and plugins are autogenerated through the sphinx conf.py script.