(doc): clarify rules for aria-invalid

index.html

@@ -879,7 +879,7 @@ <h2 id="docconformance">Document conformance requirements for use of ARIA attrib
         constraint validation</a> but that does not <a
 			  href="https://www.w3.org/TR/html/sec-forms.html#satisfy-its-constraints">satisfy its constraints</a></TD>
       <TD><code>aria-invalid=&quot;true&quot;</code></TD>
-      <TD><p>The <code>aria-invalid</code> attribute for may be used on any HTML5 elements that allow <a href="#index-aria-global">global <code>aria-*</code> attributes</a> except<em> </em><a href="https://www.w3.org/TR/html/sec-forms.html#submittable-element">submittable elements</a>   that<em> </em>have the <a href="https://www.w3.org/TR/html/sec-forms.html#element-attrdef-input-required"><code>required</code></a> attribute set. - <span class="changed-feature">(changed)</span></p></TD>
+      <TD><p>The <code>aria-invalid</code> attribute for may be used on any HTML5 elements that allow <a href="#index-aria-global">global <code>aria-*</code> attributes</a> except<em> </em><a href="https://www.w3.org/TR/html/sec-forms.html#submittable-element">submittable elements</a> that does not satisy its <em> </em><a href="https://www.w3.org/TR/html/sec-forms.html#constraints">constraints</a>. - <span class="changed-feature">(changed)</span></p></TD>
     </TR>
     <TR tabindex="-1">
       <TD>Element with <code><a href="https://www.w3.org/TR/html/editing.html#element-attrdef-global-contenteditable">contenteditable</a></code> attribute</TD>