Include docstrings from __init__ as well as the class

This enables inclusion of the parameters to the __init__, which is
very useful to have.

Change-Id: I47611df9cfe37bc01910622b17444571cf269d21
Add pre-reqs to README

Change-Id: I6966c9ff43b82572b2d86402073e5f083ebd1102
Use NumpyDoc for saner parameter docstrings

This is how I'd been writing the docs, so this now makes them render
properly.

Change-Id: Ifafaa8148b9c73c38c59864ae6e59bf0c610ff33