Implement Changelog Integration inside Dashboard

[subho007]

Integrate Headway Changelog, with a configuration to load the changelog or not via environment variables. The configuring code is:

<script>
  // @see https://docs.headwayapp.co/widget for more configuration options.
  var HW_config = {
    selector: ".CHANGE_THIS", // CSS selector where to inject the badge
    account:  "x8mO97"
  }
</script>
<script async src="https://cdn.headwayapp.co/widget.js"></script>```