Clarify description computation for aria-describedby (w3c#177)

Co-authored-by: James Craig <cookiecrook@users.noreply.github.com>

accname/index.html

@@ -270,7 +270,7 @@ <h3>Description Computation</h3>
           <th>1</th>
           <td><a class="property-reference" href="#aria-describedby"><code>aria-describedby</code></a> attribute</td>
           <td>Use on any element</td>
-          <td><a href="#mapping_additional_nd_te">Text content computation</a> on all nodes referenced by aria-describedby on the element, concatenated, and separated by a space character</td>
+          <td><a href="#mapping_additional_nd_name">Name computation</a> on all nodes referenced by aria-describedby on the element, concatenated, and separated by a space character</td>
         </tr>
         <tr>
           <th>2</th>
@@ -287,7 +287,7 @@ <h3>Description Computation</h3>
             for the HTML elements which meet this condition.
           </td>
           <td>
-            Either a <a href="#mapping_additional_nd_te">text equivalent computation</a> of the element, or as a flat string of the attribute's value.
+            Either a <a href="#mapping_additional_nd_te">text equivalent computation</a> of the host language element, or the string value of the host language attribute.
           </td>
         </tr>
         <tr>