Support integration of Piwik/Matomo in KorAP

Change-Id: I0c67971e67fe83b5c6d8d3dc584fed23c989728b
diff --git a/templates/layouts/main.html.ep b/templates/layouts/main.html.ep
index 9d9640b..966803c 100644
--- a/templates/layouts/main.html.ep
+++ b/templates/layouts/main.html.ep
@@ -78,5 +78,6 @@
     </footer>
     % };
     %= notifications 'Kalamar::Plugin::Notifications'
+    %= piwik_tag
   </body>
 </html>