Update app-service-undelete.md

Fixing title capitalization from "Restore deleted App Service app Using PowerShell" to "Restore Deleted App Service App Using PowerShell"

Author: amymcel

articles/app-service/app-service-undelete.md

@@ -8,7 +8,7 @@ ms.topic: article
 ms.custom: devx-track-azurepowershell
 ---
 
-# Restore deleted App Service app Using PowerShell
+# Restore Deleted App Service App Using PowerShell
 
 If you happened to accidentally delete your app in Azure App Service, you can restore it using the commands from the [Az PowerShell module](/powershell/azure/).