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