Documentation of exposed Haskell packages for code.world #1608

Hello! Thanks for maintaining this project!

I just want to ask something about the documentation.

Do we have a complete list of exposed Haskell packages for use on the online site? (https://code.world/haskell#). I noticed that I could import Data.Vector (vector) and Control.Monad.State (mtl).

The current reference and appendix sections on the guide page are a good start to see the documentation for code-world and other related high-level APIs, but I believe it would be better to let the user know the list of other "low-level" exposed packages/modules so they can get the general idea of what's available to use and search the doc for them somewhere else in case they'd prefer to use those modules directly for whatever reason.

Thanks :D!