update contact in CODE_OF_CONDUCT.md

Author: nulLeeKH

CODE_OF_CONDUCT.md

@@ -60,7 +60,7 @@ representative at an online or offline event.
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be
 reported to the community leaders responsible for enforcement at
-https://x.com/elizawakesup.
+[discord server](https://discord.gg/ai16z).
 All complaints will be reviewed and investigated promptly and fairly.
 
 All community leaders are obligated to respect the privacy and security of the