input: Write a function to sort a list in descending order.
  assert sort_descending([4, 6, 1, 3, 8]) == [8, 6, 4, 3, 1]
  assert sort_descending([10, 2, 33, 25, 17]) == [33, 25, 17, 10, 2]
  assert sort_descending([-1, -5, 0, 2, 3]) == [3, 2, 0, -1, -5]
output: def sort_descending(lst):
      return sorted(lst, reverse=True)