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/gitter.toml

@@ -5,6 +5,24 @@ category = "developer"
 icon = "💻"
 protocol = "rest-api"
 
+[i18n.zh]
+description = "Gitter 适配器，连接 GitHub 仓库的开发者聊天室"
+
+[i18n.zh-TW]
+description = "Gitter 適配器，連接 GitHub 儲存庫的開發者聊天室"
+
+[i18n.ja]
+description = "Gitterアダプター、GitHubリポジトリに連携した開発者チャットルーム"
+
+[i18n.ko]
+description = "Gitter 어댑터, GitHub 저장소에 연결된 개발자 채팅방"
+
+[i18n.de]
+description = "Gitter-Adapter für Entwickler-Chatrooms, die mit GitHub-Repositories verknüpft sind"
+
+[i18n.es]
+description = "Adaptador de Gitter para salas de chat de desarrolladores vinculadas a repositorios de GitHub"
+
 [metadata]
 url = "https://gitter.im"
 docs = "https://developer.gitter.im/docs/"