_includes/breadcrumbs.html

<nav class="breadcrumbs">
  <li><a href="{{ site.baseurl }}/docs/">Docs</a></li>
  {% assign doc_data = 'docs_' | append: site.active_lang %}
  {% assign page_data = site.data[doc_data].by_title[page.title] %}
  {% for doc in page_data.breadcrumbs reversed %}
    <li><a href="{{ site.baseurl }}{{ doc.url }}">{{ doc.title }}</a></li>
  {% endfor %}
  <li>{{ page.title }}</li>
</nav>