[docs] [issue30354] Change data model documentation to zero-argument super()

[Mariatta Wijaya]

Changes by Mariatta Wijaya <mariatta.wijaya at gmail.com>:


----------
stage:  -> backport needed
versions: +Python 3.5, Python 3.6

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue30354>
_______________________________________