input: Write a python function to add corresponding elements of two lists.
  assert add_list([1, 2, 3], [4, 5, 6]) == [5, 7, 9]
  assert add_list([10, 20, 30], [1, 2, 3]) == [11, 22, 33]
  assert add_list([5, 10, 15], [0, 0, 0]) == [5, 10, 15]
output: def add_list(list1, list2):
      return [x + y for x, y in zip(list1, list2)]