(Azure CXP) Added note about grayed out features for Linux apps

https://github.com/MicrosoftDocs/azure-docs/issues/52080

Author: Grace-MacJones-MSFT

articles/app-service/web-sites-integrate-with-vnet.md

@@ -19,6 +19,10 @@ Azure App Service has two variations:
 
 ## Enable VNet Integration
 
+> [!NOTE]
+> If the "Networking” blade is disabled (grayed out) in the menu for your Linux apps, it means that feature is currently not available.
+>
+
 1. Go to the **Networking** UI in the App Service portal. Under **VNet Integration**, select **Click here to configure**.
 
 1. Select **Add VNet**.