ContactHelper - AddressBook Level-3

<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent"
        aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
  <span class="navbar-toggler-icon"></span>
</button>

<div class="collapse navbar-collapse" id="navbarSupportedContent">
  <ul class="navbar-nav mr-auto">

    <!-- Project pages -->
    <li class="nav-item">
      <a class="nav-link" href="/tp/UserGuide.html">User Guide</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="/tp/DeveloperGuide.html">Developer Guide</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="/tp/AboutUs.html">About Us</a>
    </li>

    <!-- Optional: link to contact page if you have one -->
    <!--
    <li class="nav-item">
      <a class="nav-link" href="/tp/ContactUs.html">Contact</a>
    </li>
    -->

  </ul>

  <!-- Right-side links -->
  <ul class="navbar-nav ml-auto">
    <li class="nav-item">
      <a class="nav-link" target="_blank"
         href="https://github.com/AY2526S1-CS2103T-F15A-3/tp">
        GitHub
      </a>
    </li>
    <li class="nav-item">
      <a class="nav-link" target="_blank"
         href="https://github.com/AY2526S1-CS2103T-F15A-3/tp/actions">
        Build Status
      </a>
    </li>
    <li class="nav-item">
      <a class="nav-link" target="_blank"
         href="https://ay2526s1-cs2103t-f15a-3.github.io/tp/">
        Project Site
      </a>
    </li>
  </ul>
</div>