Merge pull request #422 from JSchripsema-IDM/analytics

Adds Google Tag Manager for better doc analytics

docs/_templates/page.html

@@ -13,6 +13,18 @@
 
 {% block extrahead %}
 
+<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
+new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
+j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
+'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
+})(window,document,'script','dataLayer','GTM-NK4K647');</script>
+<!-- End Google Tag Manager -->
+
+<!-- Google Tag Manager (noscript) -->
+<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-NK4K647"
+height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
+<!-- End Google Tag Manager (noscript) -->
+
 <link href="https://fonts.googleapis.com/css?family=Lato|Montserrat|Open+Sans" rel="stylesheet">
 
 {% endblock %}