Silent Gear 1.21.1 翻译提交 (#5387)

* Translation of Silent Gear

* 该路径

* Update based on 4.0.25

* 应用部分审阅意见

* Apply suggestions from code review

Co-authored-by: ZetaY <34602681+ZHAY10086@users.noreply.github.com>

* Update projects/1.21/assets/silent-gear/silentgear/lang/zh_cn.json

Co-authored-by: ZetaY <34602681+ZHAY10086@users.noreply.github.com>

* Update projects/1.21/assets/silent-gear/silentgear/lang/zh_cn.json

Co-authored-by: ZetaY <34602681+ZHAY10086@users.noreply.github.com>

* 应用审核建议 - ZY

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Co-authored-by: ZetaY <34602681+ZHAY10086@users.noreply.github.com>

Author: Cactusstudent