[skip ci] update changelog

Author: Robert Mosolgo

CHANGELOG.md

@@ -17,6 +17,7 @@
 
 - Allow custom renderers for server rendering #253
 - Server render with `renderToStaticMarkup` via `prerender: :static` #253
+- Accept `config.react.jsx_transform_options = {asset_path: "path/to/JSXTransformer.js"}` #273
 
 #### Deprecations
 
@@ -37,4 +38,4 @@
 - Component generator
 - View helper and UJS for mounting components
 - Server rendering with `prerender: true`
-- Transform `.jsx` in the asset pipeline
+- Transform `.jsx` in the asset pipeline