input: Write a python function to append an element to a list.
  assert appendElementToList([1, 2, 3], 4) == [1, 2, 3, 4]
  assert appendElementToList([], 10) == [10]
  assert appendElementToList([5, 6, 7], 8) == [5, 6, 7, 8]
output: def appendElementToList(lst, element):
      lst.append(element)
      return lst