Export CSS and just create one file

[RobbieTheWagner]

This goes back to one CSS file and adds it to exports so that folks should be able to import it.

[renews]

any ETA on this? Thanks for the lib!

[Kenneth-Sills]

@renews The only thing in the way is that the linting workflow (specifically the ATTW step) is having trouble with the CSS, which Robbie has asked about upstream. I've answer himed there for visibility, but looks like it'll be a quick fix by excluding the CSS export from type checks.