Prohibit presentation / none on where it causes conflict resolution (#1494)

Co-authored-by: Valerie Young <[email protected]>

Author: WilcoFiers

index.html

@@ -13535,6 +13535,7 @@ <h3>Presentational Roles Conflict Resolution</h3>
 <span class="comment">&lt;!-- 2. [role="none"] negates both the implicit 'heading' and the non-global aria-level. --&gt;</span>
 &lt;h1 role="none" aria-level="2"&gt; Sample Content &lt;/h1&gt;
 		</pre>
+		<p>Authors MUST NOT use <rref>presentation</rref> and <rref>none</rref> on elements where user agents will ignore that role because it conflicts with one of the above items.</p>
 	</section>
 </section>
 <section id="idl-interface" class="normative">