allow none and presentation on nav element (#404)

* allow none and presentation on nav element
* update changelog

this gets the `nav` element in alignment with other elements that would otherwise expose implicit ARIA landmarks

index.html

@@ -2058,14 +2058,16 @@ <h2 id="docconformance">
               <p>
                 Roles:
                 <a href="#index-aria-menu">`menu`</a>,
-                <a href="#index-aria-menubar">`menubar`</a>
+                <a href="#index-aria-menubar">`menubar`</a>,
+                <span class="proposed addition"><a href="#index-aria-none">`none`</a>,
+                <a href="#index-aria-presentation">`presentation`</a></span>
                 or <a href="#index-aria-tablist">`tablist`</a>
               </p>
               <p>
                 DPub Roles:
                 <a data-cite="dpub-aria-1.0#doc-index">`doc-index`</a>,
-                <a data-cite="dpub-aria-1.0#doc-pagelist">`doc-pagelist`</a>,
-                <a data-cite="dpub-aria-1.0#doc-toc">`doc-toc`</a>
+                <a data-cite="dpub-aria-1.0#doc-pagelist">`doc-pagelist`</a>
+                or <a data-cite="dpub-aria-1.0#doc-toc">`doc-toc`</a>
               </p>
               <p>
                 <a data-cite="wai-aria-1.1#global_states">Global `aria-*` attributes</a> 
@@ -4423,6 +4425,10 @@ <h2>
       <h2>Change log</h2>
       <h3>Substantive changes since the last published Recommendation</h3>
       <ul>
+        <li>
+          06-Mar-2022:
+          Allow `none` and `presentation` roles on <a href="#el-nav">`nav` element</a>.
+        </li>
         <li>
           03-Mar-2022:
           Restrict role allowances for <a href="#el-div">`div` element</a> when it is a child of a `dl` element.