input: Write a python function to find all words in a given string that start with a vowel.
  assert find_vowel_words("Apple, orange, banana") == ["Apple"]
  assert find_vowel_words("An elephant is in the room") == ["An", "elephant", "is", "in"]
  assert find_vowel_words("Umbrella, dog, cat, eagle") == ["Umbrella", "eagle"]
  assert find_vowel_words("This is an example input") == ["example", "input"]
output: def find_vowel_words(s):
      vowels = "AEIOUaeiou"
      words = s.split()
      return [word for word in words if word[0] in vowels]