Ask HN: What tool would you use to collaborate on API design across teams?

Hi HN,

We are launching 12 new projects for a coding bootcamp and we awill need to design a bunch of API-s and some of them will be shared across teams.

What tool do you see fit this situation that could help us efficiently collaborate on specs / docs? Previously some team used Google docs and MD files on Github. Would https://swagger.io be an overkill?

Thanks!