input: Write a function to sort a list of items in descending order.
  assert sort_descending([3, 7, 5, 8, 10]) == [10, 8, 7, 5, 3]
  assert sort_descending([1, 2, 3, 4, 5]) == [5, 4, 3, 2, 1]
  assert sort_descending([100, 200, 50, 300]) == [300, 200, 100, 50]
  assert sort_descending([]) == []
output: def sort_descending(lst):
      return sorted(lst, reverse=True)