add activeadmin

config/routes.rb

@@ -1,7 +1,5 @@
 Rails.application.routes.draw do
   devise_for :users, controllers: { omniauth_callbacks: 'users/omniauth_callbacks' }
-  # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html
 
-  # Defines the root path route ("/")
-  # root "articles#index"
+  ActiveAdmin.routes(self)
 end