Add 6sense script (#13448)

Author: sean1588

layouts/partials/head.html

@@ -250,6 +250,10 @@
 
     <script async defer src="https://buttons.github.io/buttons.js"></script>
 
+    {{- if eq hugo.Environment "production" }}
+        <!-- 6sense -->
+        <script async defer id="6senseWebTag" src="https://j.6sc.co/j/a4dca4b3-351c-4764-bda9-03c5caf5fedf.js"></script>
+    {{- end }}
 
     <!--Segment tracking-->
     <script>