Add upgrade process for Basic to Standard Load Balancer for VMSS

Author: Welasco

articles/load-balancer/TOC.yml

@@ -205,7 +205,7 @@
     - name: Upgrade an internal load balancer - Outbound connections required
       href: upgrade-internalbasic-to-publicstandard.md
     - name: Upgrade from Basic to Standard for Virtual Machine Scale Sets
-      href: upgrade-basic-standard-vmss.md.md
+      href: upgrade-basic-standard-vmss.md
   - name: Using multiple IP configurations
     items:
     - name: Azure portal