feat(beta): add beta badge to top header

discuss_data/static/sass/project.scss

@@ -569,6 +569,11 @@ a:hover
   font-size: larger;
 }
 
+.badge-middle {
+  padding: 0.3rem;
+  font-size: 0.9rem;
+}
+
 /*
  * User image avatar sizes
  */

discuss_data/templates/nav-top.html

 {% load static i18n wagtailcore_tags compress %}
 
 <nav class="navbar navbar-light fixed-top flex-md-nowrap p-0 border-bottom navbar-expand-sm" id="navbar-top">
-    <a class="navbar-brand px-3" href="{% url 'core.landing_page' %}"><img class="navbar-logo" src="{% static 'images/logo-primary.svg' %}" /></a>
+    <a class="navbar-brand px-3" href="{% url 'core.landing_page' %}"><img class="navbar-logo" src="{% static 'images/logo-primary.svg' %}" /></a><a class="badge badge-primary badge-middle" href="{% slugurl 'beta-version' %}">BETA</a>
 
     <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
         <span class="navbar-toggler-icon"></span>