jekyll-snippets.liquid

<!-- Wraps every three items in div.row -->
<!-- Closes div.row even there is not enough items -->

{% for item in site.data.your_data %}

  {% capture modulo %}{{ forloop.index | modulo: 3 }}{% endcapture %}

  {% if modulo == '1' %}
    <div class="row">
  {% endif %}
      <div class="col-sm-4 topic">
        {{ item.name }}
      </div>
  {% if modulo == '0' or forloop.last %}
    </div>
  {% endif %}

{% endfor %}

<!-- Output: -->
<div class="row">
  <div class="col-sm-4 topic">
    item1
  </div>
  <div class="col-sm-4 topic">
    item2
  </div>
  <div class="col-sm-4 topic">
    item3
  </div>
</div>
<div class="row">
  <div class="col-sm-4 topic">
    item4
  </div>
</div>