Add a TODO to remove "updated DefaultLocale steps" algorithm.

Author: lutien

index.bs

@@ -6238,6 +6238,8 @@ The <dfn export>WebDriver BiDi emulated language</dfn> steps given an [=environm
 
 </div>
 
+TODO: Remove the following algorithm once the update for navigator.language/s in the html spec is merged.
+
 <div algorithm="updated DefaultLocale steps">
 The [=DefaultLocale=] algorithm is implementation defined. A WebDriver-BiDi
 [=remote end=] must have an implementation that runs the following steps: