input: Write a function to check for the presence of words from a list in the content of a given URL and return a list of the found words.
  assert check_words_in_url('https://www.example.com', ['cat', 'dog', 'bird'])==['cat', 'dog']
  assert check_words_in_url('https://www.example.com', ['fish', 'lion', 'bird'])==['bird']
  assert check_words_in_url('https://www.example.com', ['tiger', 'elephant'])==[]
output: def check_words_in_url(url, words):
      import requests
      response = requests.get(url)
      content = response.text.lower()
      found_words = [word for word in words if word.lower() in content]
      return found_words