fix(doc): fix broken documentation snippets

docusaurus/docs/Flutter/05-guides/05-push-notifications/adding_push_notifications_v2.mdx

@@ -208,9 +208,9 @@ void handleNotification(
 
     flutterLocalNotificationsPlugin.show(
       1,
-      'New message from ${response.message.user.name} in ${response.channel.name}',
+      'New message from ${response.message.user!.name} in ${response.channel!.name}',
       response.message.text,
-      NotificationDetails(
+      const NotificationDetails(
           android: AndroidNotificationDetails(
         'new_message',
         'New message notifications channel',
@@ -255,7 +255,7 @@ Make sure to read the [general push notification docs](https://getstream.io/chat
 If you're not sure whether you've set up push notifications correctly, for example, you don't always receive them, or they don’t work reliably, then you can follow these steps to make sure your configuration is correct and working:
 
 1. Clone our repository for push testing: `git clone [email protected]:GetStream/chat-push-test.git`
-2. `cd flutter`
+2. `cd chat-push-test/flutter`
 3. In that folder run `flutter pub get`
 4. Input your API key and secret in `lib/main.dart`
 5. Change the bundle identifier/application ID and development team/user so you can run the app on your physical device.**Do not** run on an iOS simulator, as it will not work. Testing on an Android emulator is fine.