Specify file for adding config and show in example

I didn't know which file to add the config and it wasn't shown in the example. 
I went as far as doing a global search in github to see how other people were using it.

Thanks!
Hmm I think I tried that first but got a method error. I will try again...
On Sat, Nov 1, 2014 at 10:28 AM Calvin Yu <notifications@github.com> wrote:

> In examples/rails4/config.ru:
>
> > @@ -2,3 +2,22 @@
> >
> >  require ::File.expand_path('../config/environment',  __FILE__)
> >  run Rails.application
> > +
> > +use Rack::Cors do
>
> The configuration for the rails4 is in config/application.rb. This should
> be created as a Rack/Non-Rails example.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/cyu/rack-cors/pull/60/files#r19705229>.
>