Update CHANGELOG.md

Author: cristianoc

CHANGELOG.md

@@ -26,7 +26,7 @@ subset of the arguments, and return a curried type with the remaining ones https
 - Add support for toplevel `await` https://github.com/rescript-lang/rescript-compiler/pull/5940
 - Support optional named arguments without a final unit in uncurried functions https://github.com/rescript-lang/rescript-compiler/pull/5907
 - Add experimental suppport for directives. An annotation such as `@@directive("use client;")` emits `use client;` verbatim before imports https://github.com/rescript-lang/rescript-compiler/pull/5998
-- Add `Core` standard library support for `genType` https://github.com/rescript-lang/rescript-compiler/pull/6019
+- `genType`: add `Core` standard library support for the following builtin types: `Null.t`, `Nullable.t`, `Undefined.t`, `Dict.t<_>`, `Promise.t<_>`, `Date.t`, `BigInt.t`, `RegExp.t`, `Map.t<_, _>`, `WeakMap.t<_, _>`, `Set<_>`, `WeakSet<_>` https://github.com/rescript-lang/rescript-compiler/pull/6019
 
 #### :boom: Breaking Change