Update Windows Local Notifications docs (#2744)

* Update Windows Local Notifications docs

* Update warning about Windows App SDK notifications

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Co-authored-by: David Britch <davidbritch@users.noreply.github.com>

docs/platform-integration/local-notifications.md

@@ -453,6 +453,9 @@ Local notifications in the Windows App SDK are messages that your app can send t
 
 For information about local notifications on Windows, including implementation details for packaged and unpackaged apps, see [App notifications overview](/windows/apps/windows-app-sdk/notifications/app-notifications/).
 
+> [!WARNING]
+> Currently, scheduled notifications aren't supported in the Windows App SDK. For more information, see [Feature Request: Schedule toast notifications](https://github.com/microsoft/WindowsAppSDK/issues/5050$0).
+
 :::zone-end
 
 ## Register platform implementations