Add misssing square/square outline icon #2532

src/themes/default/elements/icon.overrides

@@ -235,6 +235,8 @@ i.icon.cube:before { content: "\f1b2"; }
 i.icon.cubes:before { content: "\f1b3"; }
 i.icon.circle.notched:before { content: "\f1ce"; }
 i.icon.circle.thin:before { content: "\f1db"; }
+i.icon.square.outline:before { content: "\f096"; }
+i.icon.square:before { content: "\f0c8"; }
 
 /* Item Selection */
 i.icon.checkmark:before { content: "\f00c"; }