docs: reference #redis-mcp-server Discord channel in contact section

Author: vchomakov

README.md

@@ -550,3 +550,5 @@ This project is licensed under the **MIT License**.
 
 ## Contact
 For questions or support, reach out via [GitHub Issues](https://github.com/redis/mcp-redis/issues).
+
+Alternatively, you can join the [Redis Discord server](https://discord.gg/redis) and ask in the `#redis-mcp-server` channel.