statically serve autotrack

Author: Andrew Ellison

_includes/scripts.html

@@ -22,7 +22,7 @@
 <!-- End Google Tag Manager (noscript) -->
 <script
   async
-  src="https://cdnjs.cloudflare.com/ajax/libs/autotrack/2.4.1/autotrack.js"
+  src="{{ site.assets_base_url }}js/autotrack.js"
 ></script>
 
 {% if page.use_recaptcha %}