Fix testing docs re: js tests
Fix testing docs re: js tests

The js tests are now run with the smoketests. This adds appropriate
notes about that.

lgp171188/fjord,hoosteeno/fjord,Ritsyy/fjord,hoosteeno/fjord,Ritsyy/fjord,Ritsyy/fjord,mozilla/fjord,lgp171188/fjord,mozilla/fjord,Ritsyy/fjord,mozilla/fjord,hoosteeno/fjord,lgp171188/fjord,hoosteeno/fjord,lgp171188/fjord,mozilla/fjord