Update toc.yml

Author: kenieva

articles/governance/service-groups/toc.yml

@@ -12,6 +12,10 @@
     href: create-service-group-member-rest-api.md
   - name: How to use Service Groups to manage resources
     href: manage-service-groups.md
+- name: Samples
+  items:
+  - name: Azure Resource Graph queries
+    href: ./resource-graph-samples.md
 - name: Reference
   items:
   - name: Resource Manager templates