Add an open source license to the repo

[kryskreative]

Summary

Comment: This repo does not have an open source license. Per the Brigade Code of Conduct, the community aims to "build tools that are open and free technology for public use."

Suggested Change: Consider adding an MIT License or using one of the Github license templates to the repo to help contributors and others clearly understand what they can or cannot do with the software that is created.

Document: Brigade Collab repo

Reference:
Brigade Code of Conduct

Adding a license to a repository