添加了国内镜像源（南大镜像）

[tangyuan0821]

先在用户可选择从国内的镜像站（南京大学开源软件镜像站）下载本项目的词库。

https://mirror.nju.edu.cn/github-chinese/

[tangyuan0821]

不过镜像源似乎是每 24 小时同步一次，可能会用延迟的问题

[yaoge123]

可以做ssh push触发更新，和cicd做到一起可以做到实时更新

[sebastionai]

Pre-merge checks · ✅ 0 · ⚠ 0 · ❌ 0 · ⏭ 3

Check	Status	Reason
PR title	⏭	Pre-merge checks could not run.
Description	⏭	Pre-merge checks could not run.
Linked issue	⏭	Pre-merge checks could not run.

[sebastionai]

Walkthrough

Adds a Nanjing University open-source mirror as an alternative download source for the userscript. The change introduces a new mirror variant of the main userscript that fetches the locale file from mirror.nju.edu.cn instead of GitHub directly. The README is updated with a new installation option linking to this mirror build.

Changes

File	Summary
Mirror userscript main.user(mirror).js	Adds a full copy of the main userscript with the @require directive pointing to the NJU mirror for the locale file.
Docs README.md	Adds a mirror installation option to the README and a corresponding reference link for the NJU mirror source.

🎯 Effort: 2 (Simple) · ⏱ ~12 minutes

_{Generated by Sebastion AI · docs}