input: Write a function to generate a list of suggestions based on a given prefix from a provided dictionary. If the dictionary is empty, the function should return an empty list.
  assert auto_complete(["dog", "deer", "deal", "dungeon", "dark", "dusk"], "d")==['dog', 'deer', 'deal', 'dungeon', 'dark', 'dusk']
  assert auto_complete(["apple", "banana", "cherry"], "b")==['banana']
  assert auto_complete(["car", "couch", "candle"], "ca")==['car', 'candle']
  assert auto_complete(["sky", "star", "sun"], "moon")==[]
  assert auto_complete([], "a")==[]
output: def auto_complete(dictionary, prefix):
      return [word for word in dictionary if word.startswith(prefix)]