bloatpad: Add icons as resources

This can serve as a useful example for how to add
themed icons as resources.

examples/bp/bloatpad.gresources.xml

@@ -4,5 +4,10 @@
   <gresource prefix="/org/gtk/bloatpad">
     <file preprocess="xml-stripblanks">gtk/menus.ui</file>
     <file preprocess="xml-stripblanks">gtk/help-overlay.ui</file>
+    <file>icons/16x16/actions/format-justify-center-symbolic.symbolic.png</file>
+    <file>icons/16x16/actions/format-justify-left-symbolic.symbolic.png</file>
+    <file>icons/16x16/actions/format-justify-right-symbolic.symbolic.png</file>
+    <file>icons/16x16/actions/view-fullscreen-symbolic.symbolic.png</file>
+    <file>icons/16x16/actions/view-restore-symbolic.symbolic.png</file>
   </gresource>
 </gresources>