add "currently" and link to fw basic

Author: vhorne

articles/firewall/easy-upgrade.md

@@ -24,7 +24,7 @@ This new capability is available through the Azure portal as shown here. It's al
 :::image type="content" source="media/premium-features/upgrade.png" alt-text="Screenshot showing SKU upgrade." lightbox="media/premium-features/upgrade.png":::
 
 > [!NOTE]
-> This new upgrade/downgrade capability doesn't support the Azure Firewall Basic SKU.
+> This new upgrade/downgrade capability doesn't currently support the [Azure Firewall Basic SKU](overview.md#azure-firewall-basic).
 
 ## Next steps