Bug#688228: python-gi: Add README.Debian explaining how to get information on the python bindings

[Stephan Lachnit]

Just reading through this issues, and this seems to be fixed a while ago.

1. The documentation for PyGObject is available now [1].
2. Gtk bindings are now in a separate package, e.g. gir1.2-gtk-3.0

I think this can be closed by now.

Regards,
Stephan Lachnit

[1] https://lazka.github.io/pgi-docs/