[gtk: 1/2] GtkApplicationWindow: Fix menubar example

[Matthias Clasen <matthiasc src gnome org>]

commit 62f7395c775a57e744c2f1a671018a80e852ddeb
Author: Emmanuel Gil Peyrot <linkmauve linkmauve fr>
Date:   Fri Sep 4 13:49:28 2020 +0200

    GtkApplicationWindow: Fix menubar example
    
    This example was using invalid attribute syntax.

 gtk/gtkapplicationwindow.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkapplicationwindow.c b/gtk/gtkapplicationwindow.c
index f8ab3d406a..b952b644c3 100644
--- a/gtk/gtkapplicationwindow.c
+++ b/gtk/gtkapplicationwindow.c
@@ -86,9 +86,16 @@
  * GtkBuilder *builder = gtk_builder_new_from_string (
  *     "<interface>"
  *     "  <menu id='menubar'>"
- *     "    <submenu label='_Edit'>"
- *     "      <item label='_Copy' action='win.copy'/>"
- *     "      <item label='_Paste' action='win.paste'/>"
+ *     "    <submenu>"
+ *     "      <attribute name='label' translatable='yes'>_Edit</attribute>"
+ *     "      <item>"
+ *     "        <attribute name='label' translatable='yes'>_Copy</attribute>"
+ *     "        <attribute name='action'>win.copy</attribute>"
+ *     "      </item>"
+ *     "      <item>"
+ *     "        <attribute name='label' translatable='yes'>_Paste</attribute>"
+ *     "        <attribute name='action'>win.paste</attribute>"
+ *     "      </item>"
  *     "    </submenu>"
  *     "  </menu>"
  *     "</interface>",