dtext links: add basic index page.

config/routes.rb

@@ -123,6 +123,7 @@ Rails.application.routes.draw do
     end
   end
   resource  :dtext_preview, :only => [:create]
+  resources :dtext_links, only: [:index]
   resources :favorites, :only => [:index, :create, :destroy]
   resources :favorite_groups do
     member do