input: Write a python function to create a dictionary where each key is a number from the list and its value is double the number.
  assert create_dictionary([3, 5, 7]) == {3: 6, 5: 10, 7: 14}
  assert create_dictionary([1, 2, 3]) == {1: 2, 2: 4, 3: 6}
  assert create_dictionary([0, 4, 8]) == {0: 0, 4: 8, 8: 16}
output: def create_dictionary(numbers):
      return {num: num * 2 for num in numbers}