Update dialog and release notes

Author: elliette

packages/devtools_app/lib/src/screens/inspector_shared/inspector_settings_dialog.dart

@@ -48,7 +48,8 @@ class FlutterInspectorSettingsDialog extends StatelessWidget {
                       'Hovering over any widget displays its properties and values.',
                   gaItem: gac.inspectorHoverEvalMode,
                 ),
-                // here
+                const SizedBox(height: largeSpacing),
+                ...dialogSubHeader(theme, 'Experimental features'),
                 CheckboxSetting(
                   notifier: preferences.inspector.inspectorV2Enabled
                       as ValueNotifier<bool?>,

packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md

@@ -20,11 +20,11 @@ with WebAssembly. - [#8270](https://github.com/flutter/devtools/pull/8270)
 
 ## Inspector updates
 
-* Added a setting that allows users to opt-in to the newly redesigned Flutter inspector. - [#8342](https://github.com/flutter/devtools/pull/8342)
+- Added a setting to the Flutter Inspector Settings dialog that allows users to opt-in to the newly redesigned Flutter Inspector. - [#8342](https://github.com/flutter/devtools/pull/8342)
 
-    ![Inspector V2 opt-in setting](images/inspector_v2_setting.png "DevTools setting to opt into the new Flutter inspector.")
+  ![Inspector V2 opt-in setting](images/inspector_v2_setting.png "DevTools setting to opt into the new Flutter Inspector.")
 
-    ![Inspector V2](images/inspector_v2.png "The new Flutter inspector.")
+  ![Inspector V2](images/inspector_v2.png "The new Flutter Inspector.")
 
 ## Performance updates