Sphinx documentation missing for public APIs

[manneohrstrom]

Add sphinx documentation to cover all public methods that form the official contract of the API and how it is intended to be used. For an example, see https://github.com/shotgunsoftware/tk-framework-shotgunutils.

[manneohrstrom]

Meeting notes:

• Move the readme content into the sphinx docs, just like we do with the AE engine.
• In the README, just add a link to the sphinx docs. (url will be https://github.com/shotgunsoftware/tk-framework-adobe)
• Add docs for the public methods that the framework exposes

[manneohrstrom]

@martinminsel i ended up doing a much more etxensive CR of the framework and i found a bunch of stuff we need to adjust. Nothing major, but important to get right ASAP. I created a bunch of v0.2 tickets.

For the docs themselves, i think we are close - see my latest PR comments - hopefully if you do a quick pass over the interfaces we can get a first iteration of the docs in place. Then we tackle the bigger items that are logged in tickets separately.

Back to you!

Thanks!

[manneohrstrom]

This didn't make it into the first release, so marking as v0.2.