Community README.md clearly describes team roles

[BradleyBoutcher]

The top-level README.md in the community repo should give a clear and detailed introduction to each team (Conjur, Cloud Solutions, Labs, etc.)

• [ ] Table of contents containing links to other sections of the readme detailing the teams
• [ ] Full sections that detail information about each group
  • [ ] "Who we are"-type section
  • [ ] "What we do"-type section
  • [ ] Dropdown table with repos owned by the team