title: Is there a gi.repository documentation for python?
body: <p>I'm looking for a <code>gi.repository</code> module documentation and I can't find anything on the internet.
  All I found is documentation of new Gtk3 libraries for C, or old <a href="http://www.pygtk.org/docs/pygtk/" rel="noreferrer">PyGtk 2.0 Reference Manual</a></p>
  
  <p>I'm looking for something like <a href="http://www.pygtk.org/docs/pygtk/" rel="noreferrer">PyGtk 2.0 Reference Manual</a> but for Gtk3.</p>
  
  <p>Is there something similar for Python? (I'm not looking for <code>dir(Gtk)</code> or <code>help(Gtk)</code> in the Python console.)</p>