Feature
Slack just is not suitable for coherent or topical conversation. Valuable information gets lost and probably the same questions are being asked multiple times. Also slack is not indexed so there's not a lot of info if you search the web.
Some people have been using stack overflow for questions like these in the past, but I don't think that's an "official" thing. Might be a good option.
I recommend https://spectrum.chat It's used by Next.js and the others. It's indexed by crawlers. Slack is the black hole.
How about a separate GitHub repo just for "help" topics?
Hey folks, thanks for asking this. Right now we use Slack because Slate's codebase is still in beta and moves quickly. We will absolutely switch to StackOverflow as the recommended place once the API is slightly more settled, so that there is less an issue with old answers being obsolete. Cheers!