input: Write a python function to capitalize each word in a list.
  assert capitalize(["apple", "banana", "strawberry"]) == ["Apple", "Banana", "Strawberry"]
  assert capitalize(["hello", "world"]) == ["Hello", "World"]
  assert capitalize(["python", "java", "c++"]) == ["Python", "Java", "C++"]
output: def capitalize(words):
      return [word.capitalize() for word in words]