chore: update Discord invite link

Author: SWHL

README.md

@@ -26,7 +26,7 @@
 <a href="https://semver.org/"><img alt="SemVer2.0" src="https://img.shields.io/badge/SemVer-2.0-brightgreen"></a>
 <a href="https://github.com/psf/black"><img src="https://img.shields.io/badge/code%20style-black-000000.svg"></a>
 
-Join our [Discord](https://discord.gg/Q9MXJ2ua)
+Join our [Discord](https://discord.gg/33eyQJq498)
 
 [简体中文](./README-CN.md) | English
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