index.html

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/html">
    <head lang="en">
        <meta charset="UTF-8">
        <title>Test Application With JS</title>
        <link href="stylesheets/style.css" rel="stylesheet" type="text/css">
    </head>

    <body>
        <header>

        </header>

        <main>
            <section class="comment-input">
                <p>Add your comment:</p>
                <input type="text"><button>+</button>
            </section>

            <section class="comments">
                <p>First comment</p>
                <p>Second comment</p>
                <p>Another comment</p>
            </section>
      </main>

        <footer>
        </footer>

        <script src="http://code.jquery.com/jquery-2.0.3.min.js"></script>
        <script src="javascripts/app.js"></script>
    </body>
</html>