Add plausible analytics

Author: jasongrout

_includes/page-header.html

@@ -14,4 +14,5 @@ <h1>{{ include.title }}</h1>
       anchors.add();
     });
   </script>
+  <script defer data-domain="jupyter.org" src="https://plausible.io/js/script.hash.outbound-links.js"></script>
 </header>