input: Write a function to sort a list of numbers in descending order.
  assert sort_descending([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])==[10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
  assert sort_descending([10, 20, 45, 67, 84, 93])==[93, 84, 67, 45, 20, 10]
  assert sort_descending([5, 7, 9, 8, 6, 4, 3])==[9, 8, 7, 6, 5, 4, 3]
output: def sort_descending(numbers):
      return sorted(numbers, reverse=True)