Description of the change

This pull request changes the output of show for Data.Set.Set and Data.Set.NonEmpty.NonEmptySet from this:

> Data.Set.fromFoldable [0, 1]
(fromFoldable (0 : 1 : Nil))

> Data.Set.NonEmpty.fromFoldable [0, 1]
(Just (fromFoldable1 (NonEmptyList (NonEmpty 0 (1 : Nil)))))

to that:

> Data.Set.fromFoldable [0, 1]
(fromFoldable [0,1])

> Data.Set.NonEmpty.fromFoldable [0, 1]
(Just (fromFoldable1 (NonEmptyArray [0,1])))

for consistency with the Show instances for maps and (non empty) lazy lists, which show arrays instead of lists for conciseness.

Close #39.

Checklist:

• Added the change to the changelog's "Unreleased" section with a reference to this PR (e.g. "- Made a change (#0000)")
• Linked any existing issues or proposals that this pull request should close
• Updated or added relevant documentation
• Added a test for the contribution (if applicable)