<richtextbox
    name="paragraphEditor"
    toolbar="default"
    height="300px"
    html="<h1>Heading 1</h1><h2>Heading 2</h2><h3>Heading 3</h3><h4>Heading 4</h4><h5>Heading 5</h5><h6>Heading 6</h6><p>Normal paragraph text.</p>" />