docs: add Discord community banner to README

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: prc5

.github/assets/discord.png

@@ -48,6 +48,14 @@ consistent interface and the best type safety in the ecosystem.
 
 <br />
 
+<p align="center">
+  <a href="https://discord.gg/DQXAJw36v">
+    <img src="./.github/assets/discord.png" alt="Join our Discord community" />
+  </a>
+</p>
+
+<br />
+
 ## Quick Start
 
 ### Define requests manually