added version to header title

Author: PhilippSalvisberg

custom-theme/partials/header.html

@@ -54,7 +54,7 @@
       <div class="md-header__ellipsis">
         <div class="md-header__topic">
           <span class="md-ellipsis">
-            {{ config.site_name }}
+            {{ config.site_name }} Version {{ config.extra.guideline_version }}
           </span>
         </div>
         <div class="md-header__topic" data-md-component="header-topic">