Request Stacked PRs

[bnb]

GitHub is shipping early access to Stacked PRs, it requires submitting a form: https://github.github.com/gh-stack/

I could just submit the form but I don't think my role as collaborator necessarily gives me the entitlement to do that for us. Honestly this is probably something we can just do - maybe a TSC member should! - but I didn't want to overstep.

[mcollina]

huge +1, I think we need it.

[mcollina]

Requested. @bensternthal I put your email as the slack channel owner that can set up a shared channel with github.

[bensternthal]

@mcollina acknowledged. Happy to help when needed.

[mcollina]

@bensternthal let us know if they add the slack channel!