input: Write a function to sort a list of integers in ascending order.
  assert sort_list([3, 7, 4, 1, 9])==[1, 3, 4, 7, 9]
  assert sort_list([10, 2, 33, 21, 5])==[2, 5, 10, 21, 33]
  assert sort_list([5, 4, 3, 2, 1])==[1, 2, 3, 4, 5]
output: def sort_list(lst):
      return sorted(lst)