Remove the word "instances" from DOMException custom bindings

Author: saschanaz

index.bs

@@ -14364,7 +14364,7 @@ as defined in the [=create an interface prototype object=] abstract operation.
 
 Additionally, if an implementation gives native {{ECMAScript/Error}} objects special powers or
 nonstandard properties (such as a <code>stack</code> property),
-it should also expose those on {{DOMException}} instances.
+it should also expose those on {{DOMException}} objects.
 
 <h4 id="es-exception-objects" dfn>Exception objects</h4>