Set up funding.yml

[bmann]

We should setup funding.yml https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/displaying-a-sponsor-button-in-your-repository

For other stuff we haven't done Github sponsors, but rather pointed at Fission fiscal host on Open Collective https://opencollective.com/fission

• @bmann setup homestar project or collective on OC