Editorial: Add section element to fix heading levels. (#1356)

Fix spelling of targeted.

index.html

@@ -13824,7 +13824,7 @@ <h2>Mapping WAI-ARIA Value types to languages</h2>
 <section class="appendix" id="changelog">
 	<h2>Change Log</h2>
 	<section>
-		<h2>Substantive changes targetted for the 1.3 release</h2>
+		<h2>Substantive changes targeted for the 1.3 release</h2>
 		<ul>
 			<li>11-Mar-2020: Add <pref>aria-braillelabel</pref></li>
 			<li>13-Feb-2020: Role <rref>suggestion</rref> added</li>
@@ -13835,6 +13835,8 @@ <h2>Substantive changes targetted for the 1.3 release</h2>
 			<li>14-Oct-2019: Add <pref>aria-brailleroledescription</pref></li>
 
 		</ul>
+	</section>
+	<section>
 		<h2>Substantive changes since the last public working draft</h2>
 		<ul>
 			<!-- EdNote: After each WD publish, move contents of this list into the next one below. -->