[perl-Gtk3] Mention that Gtk3::Widget::grab_add and grab_remove are methods in Gtk3

[Torsten Schönfeld <tsch src gnome org>]

commit 9bb8aa8c6aa417ebeb084153faf93d2dcb8f78cd
Author: Torsten Schönfeld <kaffeetisch gmx de>
Date:   Fri Jun 17 14:58:57 2016 +0200

    Mention that Gtk3::Widget::grab_add and grab_remove are methods in Gtk3

 lib/Gtk3.pm |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/lib/Gtk3.pm b/lib/Gtk3.pm
index 9ffaa37..0ba8610 100644
--- a/lib/Gtk3.pm
+++ b/lib/Gtk3.pm
@@ -2258,6 +2258,9 @@ return value.
 
 =item * Gtk3::TreeStore, Gtk3::ListStore: reorder() is currently unusable.
 
+=item * Gtk3::Widget: grab_add() and grab_remove() are methods now: C<<
+$widget->grab_add >>, C<< $widget->grab_remove >>.
+
 =item * Gtk3::Gdk::Atom: The constructor new() is not provided anymore, and the
 class function intern() must now be called as C<< Gtk3::Gdk::Atom::intern
 (name, only_if_exists) >>.