add an item to the end of a tuple.
type Result1 = Append<[1, 2], 3>; // [1, 2, 3]type Result2 = Append<[], 1>; // [1] Copy
type Result1 = Append<[1, 2], 3>; // [1, 2, 3]type Result2 = Append<[], 1>; // [1]
add an item to the end of a tuple.