Update docs and changelog

Author: alexeyr

CHANGELOG.md

@@ -26,6 +26,7 @@ Changes since the last non-beta release.
 #### Added
 
 - Configuration option `generated_component_packs_loading_strategy` to control how generated component packs are loaded. It supports `sync`, `async`, and `defer` strategies. [PR 1712](https://github.com/shakacode/react_on_rails/pull/1712) by [AbanoubGhadban](https://github.com/AbanoubGhadban).
+- The package now includes both ESM and CJS versions. [PR 1722](https://github.com/shakacode/react_on_rails/pull/1722) by [alexeyr-ci2](https://github.com/alexeyr-ci2).
 
 ### Removed (Breaking Changes)
 

docs/release-notes/15.0.0.md

@@ -30,6 +30,14 @@ Major improvements to component and store hydration:
   - `:sync` - Loads scripts synchronously (default for Shakapacker < 8.2.0) (better to upgrade to Shakapacker 8.2.0 and use `:async` strategy)
 - Improves page performance by optimizing how component packs are loaded
 
+### ESM Support
+
+The package is now published in both ES Module and CommonJS formats.
+In the next major release we'll work on making it much more tree-shakable to reduce bundle size.
+In most cases you don't need to do anything to take advantage of that,
+but if you use `require('react-on-rails')` (or `'react-on-rails/...'`),
+consider replacing it by `import`.
+
 ## Breaking Changes
 
 ### Component Hydration Changes