docs: Add an image for the XIncluded code

clutter/clutter-actor.c

@@ -109,6 +109,10 @@
  *   <xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback>
  * </xi:include>
  *   </programlisting></informalexample>
+ *   <figure id="bin-layout">
+ *     <title>Actors</title>
+ *     <graphic fileref="test-actor.png" format="PNG"/>
+ *   </figure>
  * </refsect2>
  *
  * <refsect2 id="ClutterActor-events">

doc/reference/clutter/Makefile.am

@@ -137,7 +137,8 @@ HTML_IMAGES=\
 	flow-layout-horizontal.png \
 	flow-layout-vertical.png \
 	path-alpha-func.png \
-	offscreen-redirect.png
+	offscreen-redirect.png \
+	test-actor.png
 
 # Extra SGML files that are included by $(DOC_MAIN_SGML_FILE).
 # e.g. content_files=running.sgml building.sgml changes-2.0.sgml
@@ -191,4 +192,5 @@ EXTRA_DIST += \
 	flow-layout-horizontal.png \
 	flow-layout-vertical.png \
 	path-alpha-func.png \
-	offscreen-redirect.png
+	offscreen-redirect.png \
+	test-actor.png