add haskell docs

Attempt to add Haskell docs, which I noticed are not currently live on DockerHub ( https://registry.hub.docker.com/_/haskell/ ).  Let me know if I have anything wrong and I'll fix it up.

ping @darinmorrison @ChristopherBiscardi
This is essentially what the default text says if `haskell/user-feedback.md` doesn't exist at all.  Is there a specific reason to not just use the default here?