input: Write a python function to reverse a list.
  assert reverse_list([1, 3, 5, 6, 10]) == [10, 6, 5, 3, 1]
  assert reverse_list([7, 8, 9]) == [9, 8, 7]
  assert reverse_list([4, 2, 0, -1]) == [-1, 0, 2, 4]
output: def reverse_list(lst):
      return lst[::-1]