Fix discord link (#125)

Author: tyler-griggs

README.md

@@ -3,7 +3,7 @@
 # SkyRL: A Modular Full-stack RL Library for LLMs
 
 
-[![🌐 NovaSky](https://img.shields.io/badge/-Visit%20Website-5865F2?style=for-the-badge)](https://novasky-ai.github.io/) [![Github](https://img.shields.io/badge/SkyRL-000000?style=for-the-badge&logo=github&logoColor=000&logoColor=white)](https://github.com/NovaSky-AI/SkyRL) [![Twitter](https://img.shields.io/badge/NovaSky-white?style=for-the-badge&logo=X&logoColor=000&color=000&labelColor=white)](https://x.com/NovaSkyAI) [![Hugging Face Collection](https://img.shields.io/badge/NovaSky-fcd022?style=for-the-badge&logo=huggingface&logoColor=000&labelColor)](https://huggingface.co/NovaSky-AI) [![Discord](https://img.shields.io/badge/NovaSky-5865F2?style=for-the-badge&logo=discord&logoColor=white)](https://discord.gg/AjEcBGDv) [![Documentation](https://img.shields.io/badge/Documentation-blue?style=for-the-badge&logo=readthedocs&logoColor=white)](https://skyrl.readthedocs.io/en/latest/)
+[![🌐 NovaSky](https://img.shields.io/badge/-Visit%20Website-5865F2?style=for-the-badge)](https://novasky-ai.github.io/) [![Github](https://img.shields.io/badge/SkyRL-000000?style=for-the-badge&logo=github&logoColor=000&logoColor=white)](https://github.com/NovaSky-AI/SkyRL) [![Twitter](https://img.shields.io/badge/NovaSky-white?style=for-the-badge&logo=X&logoColor=000&color=000&labelColor=white)](https://x.com/NovaSkyAI) [![Hugging Face Collection](https://img.shields.io/badge/NovaSky-fcd022?style=for-the-badge&logo=huggingface&logoColor=000&labelColor)](https://huggingface.co/NovaSky-AI) [![Discord](https://img.shields.io/badge/NovaSky-5865F2?style=for-the-badge&logo=discord&logoColor=white)](https://discord.gg/cJF2JUaaAN) [![Documentation](https://img.shields.io/badge/Documentation-blue?style=for-the-badge&logo=readthedocs&logoColor=white)](https://skyrl.readthedocs.io/en/latest/)