[css-text] Update structure of coverage report to match updated spec

Author: frivoal

css-text-3/test-coverage.html

@@ -468,7 +468,11 @@ <h3 id="first-line-indentation-the-text-indent-property">8.1 <a href="https://dr
 	<li>each-line keyword
 </ul>
 
-<h3 id="hanging-punctuation-the-hanging-punctuation-property">8.2 <a href="https://drafts.csswg.org/css-text-3/#hanging-punctuation-property">Hanging Punctuation: the hanging-punctuation property</a></h3>
+<h3 id="hanging">8.2 <a href="https://drafts.csswg.org/css-text-3/#hanging">Hanging Glyphs</a></h3>
+
+<p>Coverage TBD. Partly tested through 8.2, partly through white-space.
+
+<h4 id="hanging-punctuation-the-hanging-punctuation-property">8.2.1 <a href="https://drafts.csswg.org/css-text-3/#hanging-punctuation-property">Hanging Punctuation: the hanging-punctuation property</a></h3>
 
 <p>Spotty Coverage.