[Update] Message Format: [message]と[translation]は一意かつそれぞれ一つだけの使用に。それに伴いエラー表示や初期値の挿入など。

locales/en.yml

@@ -182,6 +182,7 @@ config_window:
     label: Message Format
     desc: "You can change the decoration of the message you want to send.\n[message] will be replaced with the message, and [translation] will be replaced with the translated message.\nIt will be used in Notification XSOverlay too."
     example_text: This is an example sentence. Fonts, line breaks, etc. may differ from the actual display.
+    error_message: "The characters '[message]' and '[translation]' cannot be used."
 
   send_message_to_vrc:
     label: Send Message To VRChat