It would be cool if people could upload type definition files for their own public-facing scripts, or upload definitions for other popular in-game scripts similar to DefinitelyTyped, and have them be merged into the global $fs / $hs / etc. object.
I don't know TypeScript configuration/tooling well enough to know if this would actually require any work in here and/or in HSE.
Probably only worth it if there is meaningful interest, otherwise it's just a complicated way of writing them for my own consumption.