Update index.bs

Fix typo on closing <dl>.

Author: yoshisatoyanagisawa

docs/index.bs

@@ -501,7 +501,7 @@ spec: storage; urlPrefix: https://storage.spec.whatwg.org/
 
                         <dt>Otherwise</dt>
                         <dd>a new {{Client}} object that represents |incumbentGlobal|'s associated worker
-                    </dd>
+                    </dl>
                 1. Let |origin| be the [=serialization of an origin|serialization=] of |incumbentSettings|'s [=environment settings object/origin=].
                 1. Let |destination| be the {{ServiceWorkerGlobalScope}} object associated with |serviceWorker|.
                 1.  Let |deserializeRecord| be <a abstract-op>StructuredDeserializeWithTransfer</a>(|serializeWithTransferResult|, |destination|'s [=global object/Realm=]).