Merge pull request #1222 from metosin/Update_changelog_1220

Update changelog after merging PR 1220

Author: mattiuusitalo

CHANGELOG.md

@@ -16,6 +16,7 @@ Malli is in well matured [alpha](README.md#alpha).
 
 ## UNRELEASED
 
+* Performance improvements in `malli.transform/transformer` [#1220](https://github.com/metosin/malli/pull/1220)
 * `malli.clj-kondo/emit!` saves to `.clj-kondo/imports` now as recommended by clj-kondo. [#1216](https://github.com/metosin/malli/pull/1216)
 
 ## 0.19.1 (2025-06-09)