Custom nested menu for Jekyll/Siteleaf

_config.yml

menu:
- title: Home
  url: /
- title: About
  url: /about
  children:
  - title: Contact
    url: /about/contact
  - title: Team
    url: /about/team
  - title: Follow us
    url: http://facebook.com/...

_includes(slash)menu.html

<ul>
{% for item in include.menu %}
  <li>
    <a href="{{item.url}}">{{item.title}}</a>
    {% if item.children.size > 0 %}{% include menu.html menu=item.children %}{% endif %}
  </li>
{% endfor %}
</ul>

default.html

{% include menu.html menu=site.menu %}