input: Write a python function to find words with a given prefix in a dictionary.
  assert auto_complete(["dog", "deer", "deal", "dungeon", "dark", "dusk"], "d") == ['dog', 'deer', 'deal', 'dungeon', 'dark', 'dusk']
  assert auto_complete(["apple", "apricot", "banana", "berry", "blueberry", "blackberry"], "b") == ['banana', 'berry', 'blueberry', 'blackberry']
  assert auto_complete(["cat", "caterpillar", "car", "carbon", "candy"], "ca") == ['cat', 'caterpillar', 'car', 'carbon', 'candy']
output: def auto_complete(dictionary, prefix):
      return [word for word in dictionary if word.startswith(prefix)]