an array of notes or a chroma set string to test against
a function that given a set returns true if is a subset of the first one
const extendsCMajor = Pcset.isSupersetOf(["C", "E", "G"])
extendsCMajor(["e6", "a", "c4", "g2"]) // => true
extendsCMajor(["c6", "e4", "g3"]) // => false
Create a function that test if a collection of notes is a superset of a given set (it contains all notes and at least one more)