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