[feature] typescript typings support

[cdaringe]

problem

i'm interested in using TypeScriptToLua with this, but it's not a supported feature

discussion

perhaps you could serve both customers by perhaps making the src a declaration file and generating the json auto-completions? or, perhaps, a DefinitelyTyped package could be created, and this package could pull that in and generate the artifacts here from it? if you're not interested, that's ok too :) . im just a bit over lua and want that TS goodness, thus am looking into it!