sedram

add Show instances for Free and Cofree

15

For instance, [Haskell has](https://hackage.haskell.org/package/free-5.1.2/docs/src/Control.Monad.Free.html#line-161) `Show1 f => Show1 (Free f)` and `(Show1 f, Show a) => Show (Free f a)` and [similarly](https://hackage.haskell.org/package/free-5.1.2/docs/src/Control.Comonad.Cofree.html#line-206) for `Cofree`. The implementation depends on my [other...

For example, @thimoteus pointed out in Slack that [a search for ](https://pursuit.purescript.org/search?q=%3C%24%3E) works fine, but [a search for ()](https://pursuit.purescript.org/search?q=%28%3C%24%3E%29) gives none of the desired results. They should probably yield the...