input: Write a function to find the shortest word in a list.
  assert find_shortest_word(["apple", "banana", "pear", "grape"]) == "pear"
  assert find_shortest_word(["elephant", "tiger", "cat", "dog"]) == "cat"
  assert find_shortest_word(["table", "chair", "desk", "couch"]) == "desk"
output: def find_shortest_word(words):
      return min(words, key=len)