Editorial: tidy up hidden enumerated attribute

Helps with whatwg#9832

source

@@ -77527,21 +77527,25 @@ END:VCARD</pre>
 
   <p>All <span>HTML elements</span> may have the <dfn element-attr for="html-global"><code
   data-x="attr-hidden">hidden</code></dfn> content attribute set. The <code
-  data-x="attr-hidden">hidden</code> attribute is an <span>enumerated attribute</span>. The
-  following table lists the states for this attribute:</p>
+  data-x="attr-hidden">hidden</code> attribute is an <span>enumerated attribute</span> with the
+  following keywords and states:</p>
 
   <table>
    <thead>
     <tr>
-     <th>State
      <th>Keywords
+     <th>State
+     <th>Brief description
    <tbody>
     <tr>
-     <td><span data-x="attr-hidden-until-found-state">Until found state</span>
      <td><dfn attr-value for="html-global/hidden"><code data-x="attr-hidden-until-found-keyword">until-found</code></dfn>
+     <td><span data-x="attr-hidden-until-found-state">Until found state</span>
+     <td>Will not be rendered but content inside will be accessible to <span>find-in-page</span> and
+     <span data-x="navigate-fragid">fragment navigation</span>
     <tr>
-     <td rowspan=2><span data-x="attr-hidden-hidden-state">Hidden state</span>
      <td>The empty string
+     <td rowspan=2><span data-x="attr-hidden-hidden-state">Hidden state</span>
+     <td rowspan=2>Will not be rendered.
     <tr>
      <td><dfn attr-value for="html-global/hidden"><code data-x="attr-hidden-hidden-keyword">hidden</code></dfn>
   </table>