Update CHANGELOG.md

Author: cristianoc

CHANGELOG.md

@@ -12,14 +12,16 @@
 
 # 12.0.0-alpha.12 (Unreleased)
 
+#### :bug: Bug fix
+- Fix issue wiht gentype and stdlib json. https://github.com/rescript-lang/rescript/pull/7378
+
 # 12.0.0-alpha.11
 
 #### :bug: Bug fix
 
 - Fix `Error.fromException`. https://github.com/rescript-lang/rescript/pull/7364
 - Fix signature of `throw`. https://github.com/rescript-lang/rescript/pull/7365
 - Fix formatter adds superfluous parens in pipe chain. https://github.com/rescript-lang/rescript/pull/7370
-- Fix issue wiht gentype and stdlib json. https://github.com/rescript-lang/rescript/pull/7378
 
 #### :house: Internal