input: Write a function to sort a list of items in descending order. The function should not return any value; instead, it should modify the list in place.
  assert sort_descending([3, 7, 5, 8, 10])==None
  sorted_list = [10, 8, 7, 5, 3]
  assert sort_descending([1, 2, 3, 4, 5])==None
  sorted_list = [5, 4, 3, 2, 1]
  assert sort_descending([10, 9, 8, 7, 6])==None
  sorted_list = [10, 9, 8, 7, 6]
  assert sort_descending([])==None
  sorted_list = []
  assert sort_descending([1])==None
  sorted_list = [1]
output: def sort_descending(lst):
      lst.sort(reverse=True)