Add billing page in preview (#2718)

Co-authored-by: codecalm <codecalm@gmail.com>

shared/data/menu.json

@@ -266,6 +266,11 @@
         "title": "Activity",
         "url": "activity.html"
       },
+      "billing": {
+        "title": "Billing",
+        "url": "billing.html",
+        "badge": "New"
+      },
       "chat": {
         "title": "Chat",
         "url": "chat.html"