Cover microcosm-devtools in the README

[solomonhawk]

What kind of issue is this? (check at least one)

• [ ] Report a bug
• [ ] Feature Request
• [ ] Question
• [ ] Discussion
• [x] Documentation
• [ ] Other, please describe:

What version of Microcosm is this for

All

Additional Comments (optional)

We should dedicate a section of the README to cover microcosm-devtools integration and usage. These tools might not yet be ready for prime-time so we may need to determine what information we can publish now even if it's just a preview or teaser.

Beyond that we should make sure that microcosm-devtools also has all the OSS stuff set up to make contribution as easy as possible.