input: def count_down(num: int) -> None:
      """Create a Python program that takes in a positive integer, then uses a while loop to output the numbers counting down to 1.
      >>> count_down(6)
      6
      5
      4
      3
      2
      1
      Done!
      """
output:     while num > 0:
          print(num)
          num -= 1
      print("Done!")