Issue #29024: Add Kivy entry to GUI FAQ

Patch by inclement.

Doc/faq/gui.rst

@@ -77,6 +77,16 @@ for Python allow you to write GTK+ 3 applications.  There is also a
 The older PyGtk bindings for the `Gtk+ 2 toolkit <http://www.gtk.org>`_ have
 been implemented by James Henstridge; see <http://www.pygtk.org>.
 
+Kivy
+----
+
+`Kivy <https://kivy.org/>`_ is a cross-platform GUI library supporting both
+desktop operating systems (Windows, macOS, Linux) and mobile devices (Android,
+iOS).  It is written in Python and Cython, and can use a range of windowing
+backends.
+
+Kivy is free and open source software distributed under the MIT license.
+
 FLTK
 ----