_includes/header.html

<nav class="navbar navbar-expand-md navbar-dark bg-dark">
  {% if page.url != "/" %}
  <a class="navbar-brand no-padding" href="{{ site.baseurl }}/"><img src="{{ site.baseurl }}/img/arrow-inverse-300px.png" height="40px"/></a>
  {% endif %}
   <button class="navbar-toggler ml-auto" type="button" data-toggle="collapse" data-target="#arrow-navbar" aria-controls="arrow-navbar" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

    <!-- Collect the nav links, forms, and other content for toggling -->
    <div class="collapse navbar-collapse justify-content-end" id="arrow-navbar">
      <ul class="nav navbar-nav">
        <li class="nav-item"><a class="nav-link" href="{{ site.baseurl }}/overview/" role="button" aria-haspopup="true" aria-expanded="false">Overview</a></li>
        <li class="nav-item"><a class="nav-link" href="{{ site.baseurl }}/faq/" role="button" aria-haspopup="true" aria-expanded="false">FAQ</a></li>
        <li class="nav-item"><a class="nav-link" href="{{ site.baseurl }}/blog" role="button" aria-haspopup="true" aria-expanded="false">Blog</a></li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#"
             id="navbarDropdownGetArrow" role="button" data-toggle="dropdown"
             aria-haspopup="true" aria-expanded="false">
             Get Arrow
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownGetArrow">
            <a class="dropdown-item" href="{{ site.baseurl }}/install/">Install</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/release/">Releases</a>
            <a class="dropdown-item" href="https://github.com/apache/arrow">Source Code</a>
          </div>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#"
             id="navbarDropdownDocumentation" role="button" data-toggle="dropdown"
             aria-haspopup="true" aria-expanded="false">
             Documentation
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownDocumentation">
            <a class="dropdown-item" href="{{ site.baseurl }}/docs">Project Docs</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/format/Columnar.html">Format</a>
            <hr/>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/c_glib">C GLib</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/cpp">C++</a>
            <a class="dropdown-item" href="https://github.com/apache/arrow/blob/main/csharp/README.md">C#</a>
            <a class="dropdown-item" href="https://godoc.org/github.com/apache/arrow/go/arrow">Go</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/java">Java</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/js">JavaScript</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/julia/">Julia</a>
            <a class="dropdown-item" href="https://github.com/apache/arrow/blob/main/matlab/README.md">MATLAB</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/python">Python</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/r">R</a>
            <a class="dropdown-item" href="https://github.com/apache/arrow/blob/main/ruby/README.md">Ruby</a>
            <a class="dropdown-item" href="https://docs.rs/arrow/latest">Rust</a>
          </div>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#"
             id="navbarDropdownSubprojects" role="button" data-toggle="dropdown"
             aria-haspopup="true" aria-expanded="false">
             Subprojects
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownSubprojects">
            <a class="dropdown-item" href="{{ site.baseurl }}/adbc">ADBC</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/format/Flight.html">Arrow Flight</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/format/FlightSql.html">Arrow Flight SQL</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/datafusion">DataFusion</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/nanoarrow">nanoarrow</a>
          </div>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#"
             id="navbarDropdownCommunity" role="button" data-toggle="dropdown"
             aria-haspopup="true" aria-expanded="false">
             Community
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownCommunity">
            <a class="dropdown-item" href="{{ site.baseurl }}/community/">Communication</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/docs/developers/contributing.html">Contributing</a>
            <a class="dropdown-item" href="https://github.com/apache/arrow/issues">Issue Tracker</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/committers/">Governance</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/use_cases/">Use Cases</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/powered_by/">Powered By</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/visual_identity/">Visual Identity</a>
            <a class="dropdown-item" href="{{ site.baseurl }}/security/">Security</a>
            <a class="dropdown-item" href="https://www.apache.org/foundation/policies/conduct.html">Code of Conduct</a>
          </div>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#"
             id="navbarDropdownASF" role="button" data-toggle="dropdown"
             aria-haspopup="true" aria-expanded="false">
             ASF Links
          </a>
          <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbarDropdownASF">
            <a class="dropdown-item" href="https://www.apache.org/">ASF Website</a>
            <a class="dropdown-item" href="https://www.apache.org/licenses/">License</a>
            <a class="dropdown-item" href="https://www.apache.org/foundation/sponsorship.html">Donate</a>
            <a class="dropdown-item" href="https://www.apache.org/foundation/thanks.html">Thanks</a>
            <a class="dropdown-item" href="https://www.apache.org/security/">Security</a>
          </div>
        </li>
      </ul>
    </div><!-- /.navbar-collapse -->
  </nav>