Add #2664 to readme

Author: Aljullu

readme.txt

@@ -132,6 +132,7 @@ Release and roadmap notes available on the [WooCommerce Developers Blog](https:/
 - enhancement: The Cart block titles have been merged into one. [#2615](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/2615)
 - enhancement: The item count badges of the Checkout block have been updated so it looks better in light & dark backgrounds. [#2619](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/2619)
 - enhancement: Checkout step progress indicator design has been updated to match the theme headings style. [#2649](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/2649)
+- performance: Reduce bundlesize of blocks using @wordpress/components directly. [#2664](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/2664)
 
 = 2.6.1 - 2020-06-01 =