docs(forms): remove deprecated forms notice for js (#2395)

Author: Foxandxss

public/docs/js/latest/guide/forms.jade

@@ -1,11 +1,5 @@
 include ../_util-fns
 
-.alert.is-important
-  :marked
-    This guide is using the new forms API. 
-    
-    The old forms API is deprecated, but we still maintain a separate version of the guide using the deprecated forms API <a href='/docs/js/latest/guide/forms-deprecated.html'>here</a>.
-
 :marked
   We’ve all used a form to login, submit a help request, place an order, book a flight,
   schedule a meeting and perform countless other data entry tasks.