Update React Editor integration and clean up template

app/collections/[handle]/editor/page.tsx

@@ -1,9 +1,11 @@
 import PageEditor from '@/components/page-editor';
 import pageData from '../page.json';
 
-// Editor for /collections/[handle]. Sitting under the route it edits means the preview
-// resolves the same params the public page gets, and `../page.json` is the
-// very file publishing writes back to.
 export default function EditorPage() {
-  return <PageEditor routeKey="/collections/[handle]" page={pageData} />;
+  return (
+    <PageEditor
+      pagePath="app/collections/[handle]/page.json"
+      page={pageData}
+    />
+  );
 }