[libadwaita/wip/exalm/window-rename: 1/2] doc: Update migration guide for the window property rename

[Alexander Mikhaylenko <alexm src gnome org>]

commit e38a1c3b7ef2d213bc375d9f2f953d21d98331b7
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Tue Aug 31 14:35:57 2021 +0500

    doc: Update migration guide for the window property rename

 doc/migrating-libhandy-1-4-to-libadwaita.md | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/doc/migrating-libhandy-1-4-to-libadwaita.md b/doc/migrating-libhandy-1-4-to-libadwaita.md
index 956afc99..fce68a3f 100644
--- a/doc/migrating-libhandy-1-4-to-libadwaita.md
+++ b/doc/migrating-libhandy-1-4-to-libadwaita.md
@@ -94,10 +94,11 @@ Same as GTK itself, all widgets that have children have a new API to replace
 The following widgets that formerly subclassed `GtkBin` have a "child" property
 now:
 
-* [class@Adw.ApplicationWindow]
 * [class@Adw.Clamp]
 * [class@Adw.StatusPage]
-* [class@Adw.Window]
+
+[class@Adw.Window] and [class@Adw.ApplicationWindow] have a "content" property
+instead.
 
 For other widgets use the following replacements: