Create and publish the API documentation

[herczy]

This should not only include the epydoc or pydoc output, but also a Wiki page on how to use codega as a Python module. Some specific examples are also needed.

[herczy]

Won't close this until I can't release automatically but for now the (incomplete, to be reviewed) API doc is uploaded)

[herczy]

Postponed to 0.5.0 until I figure out how to do this gracefully.