add 'subject' DID parameter

Signed-off-by: Brent Zundel <[email protected]>

index.html

@@ -909,6 +909,18 @@ <h2>DID Parameters</h2>
 <a data-lt="ascii string">ASCII string</a>.
               </td>
             </tr>
+            <tr>
+              <td>
+<code>subject</code>
+              </td>
+              <td>
+Indicates that the resource to be resolved is the <a>DID Subject</a>, rather
+than the <a>DID Document</a>. This parameter is used to retrieve an information
+resource identified by a <a>DID</a>. Support for this parameter is OPTIONAL.
+If present, the associated value MUST be the
+<a data-lt="ascii string">ASCII string</a> <code>true</code>.
+              </td>
+            </tr>
           </tbody>
         </table>