Add Google Analytics Support (yousinix#43)

fixes yousinix#44

Author: rribeiro1

_includes/analytics.html

@@ -0,0 +1,11 @@
+{%- if jekyll.environment == 'production' and site.analytics.enabled == true -%}
+  <!-- Global site tag (gtag.js) - Google Analytics -->
+  <script async src="https://www.googletagmanager.com/gtag/js?id={{ site.analytics.google.tracking_id }}"></script>
+  <script>
+    window.dataLayer = window.dataLayer || [];
+    function gtag(){dataLayer.push(arguments);}
+    gtag('js', new Date());
+
+    gtag('config', '{{ site.analytics.google.tracking_id }}');
+  </script>
+{%- endif -%}

_layouts/default.html

@@ -18,6 +18,7 @@
   </main>
 
   {% include footer.html %}
+  {% include analytics.html %}
   {% include scripts.html %}
 
 </body>

docs/_config.yml

@@ -63,6 +63,13 @@ collections:
 disqus: your-short-name-disqus                          # Your website Shortname on disqus
 
 
+### Analytics ###
+analytics:
+  enabled: false                                        # Set true to enable analytics
+  google:
+    tracking_id: your-google-tracking-id
+
+
 ### Defaults for collections ###
 defaults:
   - scope:

test/_config.yml

@@ -35,6 +35,13 @@ collections:
     output: true
 
 
+### Analytics ###
+analytics:
+  enabled: true
+  google:
+    tracking_id: google-tracking-id
+
+
 ### Defaults for collections ###
 defaults:
   - scope: