Update changelog

Author: diogobeda

CHANGELOG.md

@@ -7,7 +7,7 @@ If you need help upgrading `react-rails`, `webpacker` to `shakapacker`, or JS pa
 ## Unreleased
 Changes since the last non-beta release.
 
-_Please add entries here for your pull requests that are not yet released._
+- Prevent roots from being re-created when using React 18
 
 #### Changed
 - Make es6 and ts usable at same time. #1299