Update TOC to make it more discoverable.

Author: Sandeep Nair

articles/cosmos-db/mongodb/vcore/TOC.yml

@@ -23,9 +23,7 @@
     - name: MongoDB feature support
       href: compatibility.md
     - name: High availability
-      href: high-availability.md
-    - name: Migration options
-      href: migration-options.md
+      href: high-availability.md    
     - name: Security
       href: security.md
     - name: Transactions
@@ -38,6 +36,12 @@
           items:
             - name: Connect using Studio 3T
               href: connect-using-robomongo.md
+    - name: Migrate Data
+      items:
+        - name: Migration options
+          href: migration-options.md
+        - name: Migrate using MongoDB tools
+          href: migrate-with-mongotools.md
     - name: Troubleshooting and performance
       items:
         - name: Troubleshoot common issues

articles/cosmos-db/mongodb/vcore/tutorial-mongotools-cosmos-db-vcore.md renamed to articles/cosmos-db/mongodb/vcore/migrate-with-mongotools.md

@@ -40,7 +40,7 @@ This document describes the various options to lift and shift your MongoDB workl
   - *mongoexport* takes an argument specifying the subset of your existing data to export.
   - *mongoimport* opens a JSON or CSV file and inserts the content into the target database instance (Azure Cosmos DB in this case.).
   - Since JSON and CSV aren't compact formats, you may incur excess network charges as *mongoimport* sends data to Azure Cosmos DB.
-- Here's how you can [migrate data to Azure Cosmos DB for MongoDB vCore using the native MongoDB tools](./tutorial-mongotools-cosmos-db-vcore.md).
+- Here's how you can [migrate data to Azure Cosmos DB for MongoDB vCore using the native MongoDB tools](./migrate-with-mongotools.md).
 
 ## Data migration using Azure Databricks (Offline/Online)