Add sample hie.yaml files for stack and cabal

[alanz]

The cabal one is tested per component.

The stack one has issues because of the nested library.

Note: the suffix on the cabal one cannot be '.cabal', as that
extension is already used.

[fendor]

Maybe add a comment to "Get Hacking on hie" or something like that so people know what to do with these files?
Or maybe a comment for each of these files explaining what you can do with them, roughly.