Remove extraneous quote (#261)

Purely editorial, merging without approval.

index.html

@@ -1123,7 +1123,7 @@ <h3>Character</h3>
             (e.g. having different metadata elements for series vs episodes). One approach is the current one:
             "only one metadata element, the first one". Another approach is "only one metadata element,
             identified by an attribute". Another approach is "any number of metadata elements".
-            The group welcomes feedback from implementers and users."</aside>
+            The group welcomes feedback from implementers and users.</aside>
           </li>
         </ul>
         <aside class="note">As indicated in [[[#unrecognised-elements-and-attributes]]], <code>ttm:agent</code>