docs: add consent banner and GA

docs/themes/navy/layout/partial/after_footer.swig

@@ -15,4 +15,14 @@ indexName: 'liquidjs',
 inputSelector: '#search-input',
 debug: false
 });
+</script>
+
+<!-- Google tag (gtag.js) -->
+<script async src="https://www.googletagmanager.com/gtag/js?id=G-GM713991QQ"></script>
+<script>
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+
+  gtag('config', 'G-GM713991QQ');
 </script>

docs/themes/navy/layout/partial/head.swig

@@ -32,4 +32,11 @@
   <meta name="msapplication-TileImage" content="{{ url_for('icon/mstile-144x144.png') }}">
   {{ css('css/navy') }}
   {{ feed_tag('atom.xml') }}
+  <script src="https://cdn.cookiehub.eu/c2/e8e44c93.js"></script>
+  <script type="text/javascript">
+  document.addEventListener("DOMContentLoaded", function(event) {
+    var cpm = {};
+    window.cookiehub.load(cpm);
+  });
+  </script>
 </head>