Check if Target
is a union
A boolean
type Value = 'i.go.to.school.by.bus';
type IsUnionValue = IsUnion<Value>; // false
type Union = { a: string } | { b: number };
type IsUnionUnion = IsUnion<Union>; // true
type Intersection = { a: string } & { b: number };
type IsUnionIntersection = IsUnion<Intersection>; // false
IsUnion