Update checklist

prosemirror-client/index.html

@@ -185,7 +185,7 @@ <h2 id="todos">Todos</h2>
             string will create a chip and push the string into key position
           </li>
           <li>
-            <input type="checkbox" />Adding chips after a string within a group
+            <input type="checkbox" checked />Adding chips after a string within a group
             gives 'group must end with a right bracket' error — should give
             'chips not permissible within groups' error
           </li>