Recursive includes in Siteleaf / Jekyll

_includes-item.html

<li>{{ include.item.title }}
{% if include.item.items.size > 0 %}
  <ul>
  {% for item in include.item.items %}
    {% include item.html item=item %}
  {% endfor %}
  </ul>
{% endif %}
</li>

main.html

---
---
<ul>
{% for item in items %}
  {% include item.html item=item %}
{% endfor %}
</ul>