[Cosmos DB] Add ms.service to landing page

Author: markingmyname

support/azure/cosmos-db/index.yml

@@ -6,9 +6,10 @@ metadata:
   title: Troubleshoot Azure Cosmos DB issues
   description: Documentation for troubleshooting common issues with Azure Cosmos DB.
   author: seesharprun
-  editor: v-jsitser
   ms.author: sidandrews
   ms.reviewer: ouryba, v-jayaramanp
+  editor: v-jsitser
+  ms.service: azure-cosmos-db
   ms.topic: landing-page
   ms.date: 01/18/2024