Merge pull request #154 from HyeokjinKang/HyeokjinKang-patch-1

Update README.md

README.md

@@ -12,6 +12,9 @@
 [![Sponsor](https://img.shields.io/static/v1?label=Sponsor&message=%E2%9D%A4&logo=GitHub&color=%23fe8e86)](https://github.com/sponsors/HyeokjinKang)
 [![X (formerly Twitter) Follow](https://img.shields.io/twitter/follow/URLATE_)](https://twitter.com/URLATE_)
 
+> [!warning]
+> This project is still under development, and the contents below are subject to change at any time.
+
 URLATE is a open-source rhythm game built with web technologies.  
 It does not support Safari, but it is compatible with Firefox and Blink based browsers such as Chrome, Edge, and Opera.