Update "application/controller" to "application/cid".

index.html

@@ -3688,10 +3688,10 @@ <h2>IANA Considerations</h2>
       </p>
 
       <section id="controller-media-type">
-        <h2>application/controller</h2>
+        <h2>application/cid</h2>
         <p>
-This specification registers the `application/controller` media type
-specifically for identifying documents conforming to the [=controller document=]
+This specification registers the `application/cid` media type specifically for
+identifying documents conforming to the [=controllable identifier document=]
 format.
         </p>
         <table>
@@ -3710,9 +3710,9 @@ <h2>application/controller</h2>
           <tr>
             <td>Encoding considerations: </td>
             <td>
-Resources that use the `application/controller` media type are required to
-conform to all of the requirements for the `application/json` media type and are
-therefore subject to the same encoding considerations specified in Section 11 of
+Resources that use the `application/cid` media type are required to conform to
+all of the requirements for the `application/json` media type and are therefore
+subject to the same encoding considerations specified in Section 11 of
 [[[RFC7159]]].
             </td>
           </tr>