Add support for RBS

[ioquatix]

@soutaro What is the process to create/add RBS to this project? I would love to add it and expose users downstream to it, and maybe catch bugs with it too!

[havenwood]

It would be awesome to add type signatures for Async to the ruby/gem_rbs_collection repo where RBS type signatures are being collected for gems.

[havenwood]

Just adding a note to please disregard my last comment since I was confused.

I was talking with @soutaro today about ruby/gem_rbs_collection and it made me realize I totally misunderstood the purpose of the repo. Soutaro mentioned contributing to the gem_rbs_collection is really just for gem signatures maintained by someone outside the gem project. When the project maintainer wants to add signatures, contributors can just use a local sig/ directory in the gem.

[ioquatix]

I've thought about this.

I prefer to write the documentation and type signature in the code, as it's currently done.

Then, I want to convert this to RBS type signatures, and incorporate that where possible into type checking/documentation/etc.

I don't want to manually maintain the type signature nor do I think it should be in a separate gem (easy to get out of sync).

@soutaro do you have any thoughts or suggestions about how we can make this work?