The documentation you are reading is included in the docs subdirectory of the project repository. It is build using sphinx and hosted using readthedocs.
To get it running locally, install sphinx and the readthedocs theme:
$ pip install sphinx readthedocs
Documentation can then be built using the Makefile (or the make.bat for Windows):
$ make html
For quick editing, we use sphinx-autodoc.
$ pip install sphinx-autodoc
$ make livehtml