Clarify /api/vhost-limits/vhost/name PUT request

priv/www/api/index.html

@@ -969,9 +969,11 @@ <h2>Reference</h2>
         <td></td>
         <td class="path">/api/vhost-limits/<i>vhost</i>/<i>name</i></td>
         <td>
-            Set or delete per-vost limit for <code>vhost</code> with <code>name</code>.
-            Limits are set using a JSON document in the body:
-            <pre>{"max-connections": 100, "max-queues": 200}</pre>
+          Set or delete per-vhost limit for <code>vhost</code>. The <code>name</code> URL path element
+          refers to the name of the limit (<code>max-connections</code>, <code>max-queues</code>).
+          Limits are set using a JSON document in the body: <pre>{"value": 100}</pre>. Example
+          request:</br>
+          <pre>curl -4u 'guest:guest' -H 'content-type:application/json' -X PUT localhost:15672/api/vhost-limits/my-vhost/max-connections -d '{"value": 50}'</pre>
         </td>
       </tr>
     </table>