add hints to TOC

Author: Glenn Gailey

articles/azure-functions/TOC.yml

@@ -134,7 +134,7 @@
     displayName: best practice
   - name: Storage considerations
     href: storage-considerations.md
-    displayName: encryption, keys
+    displayName: encryption, keys, mount, files
   - name: Functions Proxies
     href: functions-proxies.md 
   - name: Networking options