[core/apis] adapted to build on existing data structures

docs/reference/createPlugin.md

@@ -33,7 +33,7 @@ import ExampleComponent from './components/ExampleComponent';
 export default createPlugin({
   id: 'new-plugin',
   register({ router, featureFlags }) {
-    featureFlags.registerFeatureFlag('enable-example-component');
+    featureFlags.register('enable-example-component');
 
     router.registerRoute('/new-plugin', ExampleComponent);
   },