changelog for variant type spreads

Author: zth

CHANGELOG.md

@@ -13,6 +13,7 @@
 # 11.0.0-beta.4 (Unreleased)
 #### :rocket: New Feature
 - Variants: Allow coercing from variant to variant, where applicable. https://github.com/rescript-lang/rescript-compiler/pull/6314
+- Variants: Experimental support for spreading variant type definitions, to copy constructors from one variant to another. https://github.com/rescript-lang/rescript-compiler/pull/6316
 
 #### :boom: Breaking Change
 - Fixed the issue of name collision between the newly defined Js.Json.t and the variant constructor in the existing Js.Json.kind type. To address this, the usage of the existing Js.Json.kind type can be updated to Js.Json.Kind.t. https://github.com/rescript-lang/rescript-compiler/pull/6317