Change doc analytics.

docs/mkdocs.yml

@@ -28,10 +28,6 @@ theme:
 
 copyright: "Copyright © 2016-2020 Containous"
 
-google_analytics:
-  - 'UA-51880359-3'
-  - 'docs.traefik.io'
-
 extra_css:
   - assets/styles/extra.css # Our custom styles
   - assets/styles/atom-one-light.css # HightlightJS's CSS theme

docs/theme/main.html

@@ -1,5 +1,15 @@
 {% extends "base.html" %}
 
+{% block analytics %}
+<!-- Google Tag Manager -->
+<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-NMWC63S');</script>
+<!-- End Google Tag Manager -->
+{% endblock %}
+
 {% block footer %}
 
 {% import "partials/language.html" as lang with context %}