Add Chinese README with cross-language navigation links (#801)

* Initial plan

* Add Chinese README with cross-links

Co-authored-by: rabbitism <14807942+rabbitism@users.noreply.github.com>

* chore: update Chinese README for clarity and accuracy

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: rabbitism <14807942+rabbitism@users.noreply.github.com>
Co-authored-by: Dong Bin <popmessiah@hotmail.com>

README.md

@@ -1,5 +1,7 @@
 # Ursa
 
+English | [简体中文](README.zh-CN.md)
+
 <p align="center">
     <img src="./assets/Ursa.svg" alt="drawing" width="150" />
 </p>