feat: URL 正規化（#208） (#226)

#208

Co-authored-by: miteruzo <miteruzo@naver.com>
Reviewed-on: #226

backend/config/locales/en.yml

@@ -28,4 +28,8 @@
 #       enabled: "ON"
 
 en:
-  hello: "Hello world"
+  activerecord:
+    errors:
+      messages:
+        record_invalid: "Validation failed: %{errors}"
+        taken: 'イキスギ!'