Added link to the upgrade instructions

Author: KumarVivek

powerapps-docs/sample-apps/regional-emergency-response/deploy.md

@@ -6,7 +6,7 @@ manager: annbe
 ms.service: powerapps
 ms.topic: conceptual
 ms.custom: 
-ms.date: 04/29/2020
+ms.date: 05/06/2020
 ms.author: kvivek
 ms.reviewer: kvivek
 searchScope:
@@ -26,6 +26,9 @@ Perform the following steps to deploy the Regional Government Emergency Respon
 
 Estimated time to complete these steps: 35–40 minutes.
 
+> [!IMPORTANT]
+> If you have an existing installation of this solution, follow the steps here instead to upgrade to the latest version: [Upgrade the solution](upgrade.md)
+
 ## Service URLs for US Government customers
 
 There is a different set of URLs to access Power Apps US Government environments and Power BI US Government tenants than the commercial version. The commercial version of the service URLs is used throughout this article. If you are a US Government organization, use the respective US Government URL for your deployment as mentioned here: