Update changelog

Author: DZakh

CHANGELOG.md

@@ -39,6 +39,7 @@
 
 - Add [`Deno`](https://deno.land/api?s=Deno) to reserved names, so that modules named `Deno` don't clash with the globally exposed `Deno` object. https://github.com/rescript-lang/rescript-compiler/pull/6428
 - Disable ESLint/TSLint on gentype outputs properly. https://github.com/rescript-lang/rescript-compiler/pull/6442
+- Improve `rescript` CLI to use `stdout`/`stderr` appropriately for help command's message. https://github.com/rescript-lang/rescript-compiler/pull/6439
 
 # 11.0.0-rc.4