Update Discord link

README.md

@@ -8,7 +8,7 @@
         <a href='https://lightrag.github.io'><img src='https://img.shields.io/badge/Project-Page-Green'></a>
         <a href='https://youtu.be/oageL-1I0GE'><img src='https://badges.aleen42.com/src/youtube.svg'></a>
         <a href='https://arxiv.org/abs/2410.05779'><img src='https://img.shields.io/badge/arXiv-2410.05779-b31b1b'></a>
-        <a href='https://discord.gg/rdE8YVPm'><img src='https://discordapp.com/api/guilds/1296348098003734629/widget.png?style=shield'></a>
+        <a href='https://discord.gg/yF2MmDJyGJ'><img src='https://discordapp.com/api/guilds/1296348098003734629/widget.png?style=shield'></a>
     </p>
      <p>
           <img src='https://img.shields.io/github/stars/hkuds/lightrag?color=green&style=social' />