It struck me that there was no online API documentation, which I'm assuming is simply because no one has worked on it yet.

I've put together a readthedocs branch with Python docstrings for the Encoder module (the only pure Python module in the repo), and I've manually added API documentation for the PWM module. I used sphinx to build the HTML docs locally, with which the changes are really minimal (just 3 new files under the docs directory).

I've then imported this branch to readthedocs for a proof of concept, and here it is:

http://adafruit-bbio.readthedocs.io

The nice things about readthedocs are that the maintenance is minimal (doc rebuilds are triggered from github commits) and that it allows for automatic versioning. I.e. doc builds can be tied to a particular release, so that there can be doc urls for v1.0.8, v.1.0.9, etc., along with 'stable' and 'latest' aliases.

To test this on a local checkout of that branch:

sudo pip install sphinx
cd docs
make html

And then open the docs/_build/html/index.html page with your browser. Note that the local HTML theme is the Sphinx default one, which is different than Readthedoc's online one.

Before I submit the branch, feedback and discussion would be welcome.