Merging changes synced from https://github.com/MicrosoftDocs/windows-…

…dev-docs-pr (branch live)

hub/apps/windows-app-sdk/notifications/push-notifications/push-quickstart.md

@@ -93,7 +93,8 @@ using namespace winrt::Microsoft::Windows::PushNotifications;
 
 ### Step 2: Add your COM activator to your app's manifest
 
-If your app is unpackaged (that is, it lacks package identity at runtime), then skip to **Step 3: Register for and respond to push notifications on app startup**.
+> [!IMPORTANT]
+> If your app is unpackaged (that is, it lacks package identity at runtime), then skip to **Step 3: Register for and respond to push notifications on app startup**.
 
 If your app is packaged (including packaged with external location):
 Open your **Package.appxmanifest**. Add the following inside the `<Application>` element. Replace the `Id`, `Executable`, and `DisplayName` values with those specific to your app.