Add: #600 NGルール (#602)

* Wip

* Wip

* Wip: History

* Wip: テストコード作成

* Fix test

* Wip

* Wip

* Wip

* Fix test

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* Wip

* Wip

* Wip

* なんとか完成、これから動作確認

* spell miss

* Change ng rule timings

* Fix test

* Wip

* Fix test

* Wip

* Fix form

* 表示まわりの改善

config/routes/admin.rb

@@ -34,6 +34,12 @@ namespace :admin do
   resources :warning_presets, except: [:new, :show]
   resource :ng_words, only: [:show, :create]
   resources :ngword_histories, only: [:index]
+  resources :ng_rules, except: [:show] do
+    member do
+      post :duplicate
+    end
+  end
+  resources :ng_rule_histories, only: [:show]
   resource :sensitive_words, only: [:show, :create]
   resource :special_instances, only: [:show, :create]