Update guide for Laravel Elixier to Mix

What guide do you are talking about?

Jeffrey already made a few videos about Laravel Mix:

https://laracasts.com/series/laravel-from-scratch-2017/episodes/14

https://laracasts.com/series/whats-new-in-laravel-5-4/episodes/3

And there is a dedicated page on the Laravel documention all about Mix:

https://laravel.com/docs/master/mix