[gtk: 1/2] gtk/builder: Port example to GTK 4

[Matthias Clasen <matthiasc src gnome org>]

commit aa6a9de6baa13c9f3a98e02cf00d531773aa3feb
Author: Maximiliano Sandoval R <msandova protonmail com>
Date:   Tue Jul 20 13:15:57 2021 +0200

    gtk/builder: Port example to GTK 4

 gtk/gtkbuilder.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkbuilder.c b/gtk/gtkbuilder.c
index ba31a8820c..02d87ea30d 100644
--- a/gtk/gtkbuilder.c
+++ b/gtk/gtkbuilder.c
@@ -171,13 +171,14 @@
  * ```xml
  * <interface>
  *   <object class="GtkDialog" id="dialog1">
- *     <child internal-child="vbox">
+ *     <child internal-child="content_area">
  *       <object class="GtkBox" id="vbox1">
  *         <child internal-child="action_area">
  *           <object class="GtkBox" id="hbuttonbox1">
  *             <child>
  *               <object class="GtkButton" id="ok_button">
- *                 <property name="label">gtk-ok</property>
+ *                 <property name="label" translatable="yes">_Ok</property>
+ *                 <property name="use-underline">True</property>
  *                 <signal name="clicked" handler="ok_button_clicked"/>
  *               </object>
  *             </child>