Semigroup a => Monoid (Maybe a)

[tomjaguarpaw]

Lift a semigroup into Maybe forming a Monoid according to http://en.wikipedia.org/wiki/Monoid: "Any semigroup S may be turned into a monoid simply by adjoining an element e not in S and defining ee = e and es = s = s*e for all s ∈ S."

https://hackage.haskell.org/package/base-4.17.0.0/docs/Data-Maybe.html#t:Monoid

What??

Reported at https://nitter.net/Profpatsch/status/1585538320578367489