chore: remove additional text from changelog and add to docu

Signed-off-by: ElaineDeMattosSilvaB <elaine.mattos@gmail.com>

.changeset/eager-toes-rest.md

@@ -4,20 +4,3 @@
 ---
 
 Add optional `description` field to plugin-level feature flags.
-
-Plugin developers can now provide an optional description for their feature flags:
-
-```ts
-export const myPlugin = createPlugin({
-  id: 'my-plugin',
-  featureFlags: [
-    {
-      name: 'show-beta-feature',
-      description: 'Enables the new beta dashboard view',
-    },
-  ],
-});
-
-If no description is provided, the default "Registered in {pluginId} plugin" message is shown.
-
-```

docs/plugins/feature-flags.md

@@ -19,11 +19,17 @@ import { createPlugin } from '@backstage/core-plugin-api';
 
 export const examplePlugin = createPlugin({
   // ...
-  featureFlags: [{ name: 'show-example-feature' }],
+  featureFlags: [
+    {
+      name: 'show-example-feature',
+      description: 'Enables the new beta dashboard view',
+    },
   // ...
 });
 ```
 
+Note that the `description` property is optional. If not provided, the default "Registered in {pluginId} plugin" message is shown.
+
 ### In the application
 
 Defining a feature flag in the application is done by adding feature flags in `featureFlags` array in the