navbar.html

<nav class="navbar navbar-default navbar-fixed-top" role="navigation">
  <!-- Brand and toggle get grouped for better mobile display -->
  <div class="navbar-header">
    <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-ex1-collapse">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>
    <a class="navbar-brand" href="index.html">select2-bootstrap-css</a>
  </div>

  <!-- Collect the nav links, forms, and other content for toggling -->
  <div class="collapse navbar-collapse navbar-ex1-collapse">
    <ul class="nav navbar-nav">
      {% for version in site.versions %}
        <li class="{% if version == page.version %}active{% endif %}"><a href="{{ version }}.html">{{ version }}</a></li>
      {% endfor %}
    </ul>
  </div><!-- /.navbar-collapse -->
</nav>