Add placeholder pages for Domains and Accounts; mark current page in navbar

templates/accounts.html.twig

@@ -0,0 +1,10 @@
+{% extends "base.html.twig" %}
+
+{% block title %}Accounts{% endblock %}
+
+{% block content %}
+    <h2>Accounts</h2>
+
+    <p>List of accounts ... <b>TODO</b></p>
+    <p><a href="/accounts/42">Test</a></p>
+{% endblock %}