Mirror/docs/_includes/sidebar.html

<div  class="col-12 col-md-3 col-xl-2 bd-sidebar">
    
    <nav class="collapse bd-links" id = "sidebar">
        {% for child in site.data.navigation %}
            <div class="bd-toc-item">            
                {% assign childid = ("submenu_" | append: forloop.index) %}
                {% include f_sidebar_nav.html item=child id=childid %}
            </div>
        {% endfor %}
    </nav>
</div>