feat: add i18n descriptions to all hands and channels (#22)

Add [i18n.zh], [i18n.zh-TW], [i18n.ja], [i18n.ko], [i18n.de], [i18n.es]
sections with translated descriptions to:
- 15 Hand TOML files (hands/*/HAND.toml)
- 44 Channel TOML files (channels/*.toml)

This enables the website to display localized Hand and Channel descriptions
based on the user's selected language.

channels/twitch.toml

@@ -5,6 +5,24 @@ category = "social"
 icon = "🎮"
 protocol = "irc"
 
+[i18n.zh]
+description = "Twitch 适配器，在 Twitch 直播聊天中收发消息"
+
+[i18n.zh-TW]
+description = "Twitch 適配器，在 Twitch 直播聊天中收發訊息"
+
+[i18n.ja]
+description = "Twitchアダプター、Twitch配信チャットでのメッセージの読み取りと送信"
+
+[i18n.ko]
+description = "Twitch 어댑터, Twitch 스트림 채팅에서 메시지 읽기 및 전송"
+
+[i18n.de]
+description = "Twitch-Adapter zum Lesen und Senden von Nachrichten in Twitch-Stream-Chats"
+
+[i18n.es]
+description = "Adaptador de Twitch para leer y enviar mensajes en chats de transmisiones de Twitch"
+
 [metadata]
 url = "https://www.twitch.tv"
 docs = "https://dev.twitch.tv/docs/irc/"