views-view-unformatted--home-news.html.twig
Within {% for row in rows %} we can use {{ loop.index }} like: <article id="newsitem{{ loop.index }}">.
Full output might look like:
{% for row in rows %} <article id="newsitem{{ loop.index }}" class="newsitem col-md-4 col-lg-4 col-sm-6 col-xs-12"> {{- row.content -}} </article> {% endfor %}
Main Category
Secondary Categories