Menu subtitle

<header>
    <div class="navbar navbar-default" role="navigation">
        <div class="navbar navbar-main">
            <div class="container">
                <div class="navbar-header">
                    <a class="navbar-brand" href="../../index.html"><img src="../../images/logo.png" alt="logo" /></a>
                    <button type="button" class="navbar-toggle">
                        <i class="fa fa-bars"></i> 
                    </button>
                </div>
                <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
                    <ul class="nav navbar-nav subheader-bootstrap">
                        <li class="active"><a href="#">Home<span class="sub">Go back</span></a></li>
                        <li class="dropdown">
                            <a class="dropdown-toggle" data-toggle="dropdown" href="#">Dropdown<i class="caret"></i>
                                <span class="sub">A simple list</span>
                            </a>
                            <ul class="dropdown-menu multi-level">
                                <li><a href="#">Action</a></li>
                                <li><a href="#">Another action</a></li>
                                <li><a href="#">Something else here</a></li>
                            </ul>
                        </li>
                        <li><a href="#">About<span class="sub">Who we are</span></a></li>
                        <li><a href="#">Services<span class="sub">Our core business</span></a></li>
                        <li><a href="#">Contact us<span class="sub">We answer 24/7</span></a></li>
                    </ul>
                </div>
            </div>
        </div>
    </div>
</header>