fixed error in TOC

Author: priestlg

articles/databox-online/TOC.yml

@@ -89,6 +89,7 @@
       href: azure-stack-edge-security.md
     - name: Review specifications
       href: azure-stack-edge-technical-specifications-compliance.md
+      items:
       - name: Regional power cords
         href: azure-stack-edge-technical-specifications-powercords-regional.md
   - name: How to