Update changelog

Author: yuhan0

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- [#483](https://github.com/clojure-emacs/clj-refactor.el/issues/483): Improve performance of cljr-slash when typing fraction literals.
 - [#482](https://github.com/clojure-emacs/clj-refactor.el/issues/482): Add missing defgroup form.
 - [#470](https://github.com/clojure-emacs/clj-refactor.el/issues/470): Choose `deps.edn` over `pom.xml` as project file.