#9 Add a MINIMAL pragma

The documentation says

If you want a manually-defined instance, but don't wish to define every method, only fromFinite and toFinite are needed, along with Cardinality.

Adding a MINIMAL pragma would reflect that in the haddocks, which currently say

Minimal complete definition: Nothing

due to the default methods.

P.S. The hackage page for this library currently says "Deprecated." for all versions, when I assume this text is only meant to appear for the older versions?

This is because MINIMAL pragmata interfere with derivation-via-Generics. It's annoying, but a known problem.

Also, I am no longer working on finitary (hence the deprecation). If you'd like it, please let me know.