_includes/nav_header.html

<div class="masthead">
    <p class="lead">
        <a href="{{ site.url }}index.html"><img src="{{ site.url }}img/asterixdb.png" style="height:75px; width:auto; vertical-align:bottom; margin-top:10px;"/></a>
    </p>
</div>

<nav class="navbar navbar-default">
        <div class="container">
          <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target=".navbar-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="{{ site.url }}index.html">Overview</a>
          </div>
          <div class="navbar-collapse collapse">
            <ul class="nav navbar-nav">
              <li><a href="{{ site.url }}download.html">Download</a></li>
              <li class="dropdown">
                <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">Documentation<span class="caret"></span></a>
                <ul class="dropdown-menu" role="menu">
                  <li class="dropdown-header">Stable release</li>
                  <li><a href="{{ site.DOCS_BASE_URL }}/{{ site.STABLE_VERSION }}/index.html">Documentation for {{ site.STABLE_VERSION }}<i class="fa fa-external-link fa-sm"></i></a></li>
                  <li class="divider"></li>
                  <li class="dropdown-header">Snapshot release</li>
                  <li><a href="{{ site.UNSTABLE_DOCS_BASE_URL }}index.html">Documentation for {{ site.UNSTABLE_VERSION }}  <i class="fa fa-external-link fa-sm"></i></a></li>
                </ul>
              </li>
              <li><a href="{{ site.url }}about.html">About</a></li>
              <li><a href="{{ site.url }}community.html">Community</a></li>
              <li class="dropdown">
                <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">Contributing <span class="caret"></span></a>
                <ul class="dropdown-menu" role="menu">
                  <li class="dropdown-header">For New Contributors</li>
                  <li><a href="{{ site.url }}dev-setup.html">Development Setup</a></li>
                  <li class="divider"></li>
                  <li class="dropdown-header">For Committers</li>
                  <li><a href="{{ site.url }}pushing.html">Pushing changes</a></li>
                  <li><a href="{{ site.url }}site.html">Editing this site</a></li>
                </ul>
              </li>
            </ul>
          </div><!--/.nav-collapse -->
        </div>
      </nav>