misc: declare viewport to get responsive mode on mobile chrome (#24153)

gadjo/templates/gadjo/root.html

@@ -4,6 +4,7 @@
     <meta charset="utf-8"/>
     <title>{% block page-title %}{% endblock %}</title>
     <link rel="stylesheet" type="text/css" media="all" href="{% static "css/gadjo.css" %}?{% start_timestamp %} "/>
+    <meta name="viewport" content="width=device-width, initial-scale=1">
     <meta http-equiv="X-UA-Compatible" content="IE=edge" />
     {% block gadjo-js %}
     <script src="{% xstatic 'jquery' 'jquery.min.js' %}"></script>