input: Write a python function to encrypt a given text by shifting each letter two positions forward in the ASCII table. Non-alphabetical characters should remain unchanged.
  assert encrypt("Hello, world!") == "Jgnnq, yqtnf!"
  assert encrypt("Python123!") == "Ravjqp123!"
  assert encrypt("A B C") == "C D E"
output: def encrypt(text):
      encrypted_text = ''
      for char in text:
          if char.isalpha():
              encrypted_text += chr(ord(char) + 2)
          else:
              encrypted_text += char
      return encrypted_text