Support definition lists (finally!)

[LesML] / TESTING / 📤 / hgroup

<?xml version="1.0"?>
<div xmlns="http://www.w3.org/1999/xhtml"><article lang="en" xml:lang="en"><div class="body"><hgroup><p>Start HGROUP</p><h1 lang="en" xml:lang="en">My Test Document</h1><p>End HGROUP</p></hgroup><hgroup><h2>
An amazing document</h2><p>End another HGROUP</p></hgroup></div></article></div>