input: Write a python function to check if an intent is present in a message.
  assert check_intent("Hi, I'm here to answer any questions you have about programming languages.") == 'greeting'
  assert check_intent("Python is a high-level programming language, often used for creating dynamic web applications and data science.") == 'python'
  assert check_intent("What is JavaScript?") == 'javascript'
  assert check_intent("Tell me about Java.") == 'java'
  assert check_intent("What is Ruby?") == None
output: def check_intent(message):
      intents = {
          'greeting': ["hi", "hello", "hey"],
          'python': ["python"],
          'javascript': ["javascript"],
          'java': ["java"],
          'ruby': ["ruby"]
      }
      
      message_lower = message.lower()
      
      for intent, keywords in intents.items():
          for keyword in keywords:
              if keyword in message_lower:
                  return intent
      
      return None