bug#29003: 25.3; Docstring from PEP 257 is filled incorrectly by Emacs

[Radon Rosborough]

> I think all Emacs fill commands will fill this as one continous
> line,

As it currently stands, yes. That doesn't have to be the case,
however. For example, package `python-docstring' can understand reST
syntax, so that:

    def example_function():
        """Initialize engine.

        :param holes: Number of holes.
        :param rounds: Number of rounds.
        :param colors: Number of colors.

        :returns: Game engine instance.
        """
        pass

is not modified when filled. The question is whether the example given
by PEP 257 should be considered "standard" syntax for introducing
keyword arguments, and whether such syntax should be supported by
Emacs in a similar way to how `python-docstring' supports reST syntax.