Flow support #2
Description
I was supporting Flow declarations in the past, but still was struggling with some typedef semantics and tooling even when my knowledge was on point. Now I can't provide up-to-date flow decls, because all of my projects are TS. But I still got some tooling built in the repo which I don't want to just remove. If someone want to use this and is an active Flow user, I would gladly accept a PR to sort out everything flow-related.