Restore the minus sign before the default value of tabIndex getter

The changes in #11450 inadvertently removed the minus sign in front of the default value for the tabIndex getter.

Author: mrobinson

source

@@ -85143,7 +85143,7 @@ dictionary <dfn dictionary>CommandEventInit</dfn> : <span>EventInit</span> {
    <code>button</code>, <code>frame</code>, <code>iframe</code>, <code>input</code>,
    <code>object</code>, <code>select</code>, <code>textarea</code>, or <span>SVG
    <code>a</code></span> element, or is a <code>summary</code> element that is a <span>summary for
-   its parent details</span>; otherwise 1.</p></li>
+   its parent details</span>; otherwise &#x2212;1.</p></li>
   </ol>
   </div>
 
@@ -157180,6 +157180,7 @@ INSERT INTERFACES HERE
   Martin Janecke,
   Martin Kutschker,
   Martin Nilsson,
+  Martin Robinson,
   Martin Thomson,
   Masataka Yakura,
   Masatoshi Kimura,