add little nav menu for categorizations

dlibrary/templates/list.html

@@ -2,6 +2,7 @@
 {% block body %}
 {% from 'utils.html' import root with context %}
 <h1 id="list-title"><a href="{{ root() }}">DLibrary</a>{% if categorization %} &gt; <a href="{{ root() }}{{ categorization }}">{{ categorization.capitalize() }}</a>{% endif %}{% if title %} &gt; {{ title }}{% endif %}</h1>
+<div class="nav">{% for c in ['circles', 'authors', 'tags', 'series'] %}<div class="nav-item"><a href="{{ root() }}{{ c }}">{{ c.capitalize() }}</a></div>{% endfor %}</div>
 <div class="card-listing">
   {% for work in works %}
   <div class="card">