let link to haddock documentation point to stackage

[soenkehahn]

No description provided.

[jkarni]

This points to a specific version, which means we'll have to keep updating it every time there's a release. I haven't found a stackage equivalent of "latest" - if there isn't one, I propose we keep it as is.

I know the link is now broken, but that's because the haddocks haven't been built. I'll try uploading the package again.

[jkarni]

Docs uploaded.

[soenkehahn]

Thanks a lot.