update changelog

Author: puredanger

README.md

@@ -66,6 +66,7 @@ Copyright © Rich Hickey and contributors
 ## Changelog
 
 * next
+  * [ASYNC-256](https://clojure.atlassian.net/browse/ASYNC-256) (CLJ) Add io-thread and System property clojure.core.async.executor-factory
   * [ASYNC-255](https://clojure.atlassian.net/browse/ASYNC-255) (CLJ) alts guards against put of nil message on entry
   * Update tools.analyzer.jvm to 1.3.2
 * Release 1.7.701 on 2024.12.17