Update the README to define the group #20
Description
Use Jeff's practitioners group as an example: https://github.com/solid-contrib/practitioners
Include, at a minimum:
Goals: What are we trying to accomplish with the repo, and the site? An introduction to developers to get started working on apps, or something more?
Audience: Is it intended for potential Solid app developers? What about pod providers, etc.?
Scope: What kinds of features should we focus on? What would be beyond our current resources?