Update metadata desc

Author: alvinashcraft

hub/apps/windows-app-sdk/applifecycle/background-tasks.md

@@ -1,6 +1,6 @@
 ---
 title: Using background tasks in Windows apps
-description: This article provides an overview of using background tasks and describes how to create a new background task in a WinUI app.
+description: This article provides an overview of using background tasks and describes how to create a new background task in a WinUI app with the Windows App SDK BackgroundTaskBuilder APIs.
 ms.date: 01/05/2025
 ms.topic: concept-article
 keywords: windows 11, winui, background task, app lifecycle, windows app sdk