Publish to JSR

[AaronDewes]

I'd like to publish Probot to https://jsr.io/, an alternative package registry created by the Deno team during CI once we move to ESM.

Would that be okay with you? @gr2m @wolfy1339 @Uzlopak

I registered the @probot scope on JSR (JSR only supports scoped packaged), so the name is reserved for us. If any of you get access to JSR, I can invite you to the JSR scope.