weston.ini: document background-type
diff --git a/weston.ini b/weston.ini
index c6cff76..cd34044 100644
--- a/weston.ini
+++ b/weston.ini
@@ -4,6 +4,7 @@
 [shell]
 background-image=/usr/share/backgrounds/gnome/Aqua.jpg
 background-color=0xff002244
+background-type=tile
 panel-color=0x90ff0000
 locking=true
 animation=zoom