divide for loop by n

divide-loop.twig

{% for col in posts|batch((posts|length / 2)|round(0, 'ceil')) %}
    <div class="col-12 col-sm-6">
      {% for item in col %}
        <a href="{{ item.link }}">
          {{ item.title }}
        </a>
      {% endfor %}
    </div>
  {% endfor %}