input: Write a python function to sort a list of integers in descending order.
  assert sort_descending([4, 7, 1, 10, 3]) == [10, 7, 4, 3, 1]
  assert sort_descending([5, 3, 9, 1, 6]) == [9, 6, 5, 3, 1]
  assert sort_descending([8, 2, 7, 5, 4]) == [8, 7, 5, 4, 2]
output: def sort_descending(lst):
      return sorted(lst, reverse=True)