Documentation on setting up a dev environment. A README.md?

[williamkunz]

I am a long time user and would love some direction on how to get a dev environment going so I can contribute.

[rhurling]

I would really like some direction as well, since I want to extend DockerUpdate to correctly work with private registries. I've already worked out what needs to be changed in the process (which api calls need to be made to get a token, which extra header need to be send with pulling an image), but I can't work out how to setup a dev environment.