Add maintainers list

[jonbartels]

Add maintainers list. Update maintainers and SC with links. Add links to governance document.

On approval, users in the maintainers list will be granted permission to approve PRs in the engine repo and other technical repositories.

[kpalang]

@mgaffigan and @NicoPiel - I'd love to get your formal ack and an agreement here, too :)

[mgaffigan]

@kpalang, let's go!

[NicoPiel]

@kpalang acknowledged 😎

[tonygermano]

I want to start by saying that I'm highly appreciative of the amount of effort Nico has already contributed to working on the Gradle conversion.

However, I would like to see a bit more from him before granting maintainer rights. A primary responsibility of being a maintainer is helping to improve other people's PRs by giving thoughtful reviews with constructive feedback. If he's interested in the position, I'd love to see him start to review some of the open PRs.

I'm not approving Nico right now, but my vote is a "not yet" rather than a "no."

[tonygermano]

I'm a "yes" on Mitch. I think he's done a superb job not only in the volume and quality of his contributions, but also in assisting with PRs contributed by others, responding to open issues, and offering general assistance to other users and developers in discord.

[jonbartels]

Split into two separate PRs:

• Create separate maintainers file; Add MitchG; update links #35 for Mitch G and link cleanup
• Add nico piel as maintainer #36 for Nico