[pagex] implement visibility flags

[voidcannon] migrate to visibility flags

content/editorial/home-debug/home-debug.pagex.js

@@ -1,6 +1,6 @@
 import {
     VoidcannonContentType,
-    VoidcannonSectionType
+    VoidcannonSectionType, VoidcannonVisibilityFlags
 } from "voidcannon";
 
 import {PagexResourceTransformer} from "pagex";
@@ -85,5 +85,8 @@ export default {
             label: "Various Articles",
             target: "collections/featured"
         },
+    ],
+    visibility_flags: [
+        VoidcannonVisibilityFlags.HIDDEN_IN_SITEMAP
     ]
 }