Django (Bootstrap) Active Menu

menu.html

Sure, you could make a Template Tag. But if it's just a single main menu in the entire website.. why not just:
(Not really limited to bootstrap, just an example)

<ul class="navbar-nav">
  {% with request.resolver_match.url_name as url_name %}
    <li class="nav-item">
      <a class="nav-link{% if url_name == "home" %} active{% endif %}" href="{% url "app:home" %}">Home</a>
    </li>
    <li class="nav-item">
      <a class="nav-link{% if url_name == "news" %} active{% endif %}" href="{% url "app:news" %}">News</a>
    </li>
  {% endwith %}
</ul>