input: def encrypt(message: str, key: str) -> str:
      """Encrypt a message using a key by shifting each character in the message by the ASCII value of the first character of the key.
      >>> encrypt("Hello world!", "secret")
      "e¦İƏǁ'*—-»"
      """
output:     
      encrypted_message = ""
      shift = ord(key[0])
      for char in message:
          encrypted_message += chr(ord(char) + shift)
      return encrypted_message
  