input: Write a python function to create a 2D list of size n x n filled with zeros.
  assert create_2d_list(3) == [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
  assert create_2d_list(5) == [[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]]
  assert create_2d_list(2) == [[0, 0], [0, 0]]
output: def create_2d_list(n):
      return [[0 for _ in range(n)] for _ in range(n)]