[docs] added skeleton

docs/reference/createPlugin.md

@@ -17,13 +17,14 @@ type PluginHooks = {
 };
 ```
 
-[Read more about the router here](createPlugin-router.md)
+- [Read more about the router here](createPlugin-router.md)
+- [Read more about feature flags here](createPlugin-feature-flags.md)
 
 ## Example Uses
 
 ### Creating a basic plugin
 
-Showcasing adding multiple routes and a redirect.
+Showcasing adding multiple routes, a feature flag and a redirect.
 
 ```jsx
 import { createPlugin } from '@backstage/core';
@@ -31,7 +32,9 @@ import ExampleComponent from './components/ExampleComponent';
 
 export default createPlugin({
   id: 'new-plugin',
-  register({ router }) {
+  register({ router, featureFlags: { registerFeatureFlag } }) {
+    registerFeatureFlag('enable-example-component');
+
     router.registerRoute('/new-plugin', ExampleComponent);
   },
 });