input: Write a python function to encode and decode a given text by shifting ASCII values by +1 and -1 respectively.
  assert encode('Python') == 'Qzuipo'
  assert decode('Qzuipo') == 'Python'
  assert encode('Hello, World!') == 'Ifmmp-!Xpsme"'
  assert decode('Ifmmp-!Xpsme"') == 'Hello, World!'
  assert encode('abc') == 'bcd'
  assert decode('bcd') == 'abc'
output: def encode(text):
      return ''.join(chr(ord(char) + 1) for char in text)
  
  def decode(text):
      return ''.join(chr(ord(char) - 1) for char in text)