input: Write a python function to generate all possible combinations of two words from a given list using itertools.combinations.
  assert generate_combinations(["cat", "dog", "pizza", "coffee"]) == [('cat', 'dog'), ('cat', 'pizza'), ('cat', 'coffee'), ('dog', 'pizza'), ('dog', 'coffee'), ('pizza', 'coffee')]
  assert generate_combinations(["apple", "banana", "cherry"]) == [('apple', 'banana'), ('apple', 'cherry'), ('banana', 'cherry')]
  assert generate_combinations(["red", "blue", "green", "yellow"]) == [('red', 'blue'), ('red', 'green'), ('red', 'yellow'), ('blue', 'green'), ('blue', 'yellow'), ('green', 'yellow')]
output: def generate_combinations(words):
      from itertools import combinations
      return list(combinations(words, 2))