Add changelog

Author: cometkim

CHANGELOG.md

@@ -21,6 +21,7 @@
 
 - Add shift (`<<`, `>>`, `>>>`) operators for `int` and `bigint`. https://github.com/rescript-lang/rescript/pull/7183
 - Add bitwise AND (`&`) operator for `int` and `bigint`. https://github.com/rescript-lang/rescript/pull/7415
+- Add bitwise NOT (`~`) operator for `int` and `bigint`. https://github.com/rescript-lang/rescript/pull/7418
 - Significantly reduced the download size by splitting binaries into optional platform-specific dependencies (e.g, `@rescript/linux-x64`). https://github.com/rescript-lang/rescript/pull/7395
 - JSX: do not error on ref as prop anymore (which is allowed in React 19). https://github.com/rescript-lang/rescript/pull/7420