Update TOC.yml

Author: gahl-levy

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

@@ -47,7 +47,9 @@
     - name: Compute and storage
       href: compute-storage.md 
     - name: Migration options
-      href: migration-options.md 
+      href: migration-options.md
+    - name: Service limits
+      href: limits.md
     - name: Security
       items: 
         - name: Security overview