#21 完了

backend/config/routes.rb

@@ -24,6 +24,7 @@ Rails.application.routes.draw do
   get "tags/create"
   get "tags/update"
   get "tags/destroy"
+  get 'tags/autocomplete', to: 'tags#autocomplete'
   get "tag_aliases/index"
   get "tag_aliases/show"
   get "tag_aliases/create"