[gtk+] window: Expand CSS node docs

[Timm Bäder <baedert src gnome org>]

commit 68383cfcd331e022771a913e3ed52ee66c911d25
Author: Timm Bäder <mail baedert org>
Date:   Mon Apr 24 15:12:23 2017 +0200

    window: Expand CSS node docs

 gtk/gtkwindow.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 2664506..0c63689 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -132,8 +132,9 @@
  * # CSS nodes
  *
  * |[<!-- language="plain" -->
- * window
+ * window.background
  * ├── decoration
+ * ├── <titlebar child>.titlebar [.default-decoration]
  * ╰── <child>
  * ]|
  *