add changelog to readme.txt

Author: nerrad

readme.txt

@@ -85,6 +85,25 @@ Release and roadmap notes available on the [WooCommerce Developers Blog](https:/
 
 == Changelog ==
 
+= 3.4.0 - 2020-09-14 =
+
+#### Bug Fixes
+
+- Ensure shopper saved card is used as default payment method (default was being overwritten in some circumstances). ([3131](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3131))
+- Fix Cart & Checkout sidebar layout broken in some themes. ([3111](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3111))
+- Fix product reviews schema date fields to use new (WP 5.5) `date-time` format. ([3109](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3109))
+- Use wp_login_url instead of hardcoding login path. ([3090](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3090))
+- Fix an issue with COD not showing when first enabled. ([3088](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3088))
+- Fix JS console error when COD is enabled and no shipping method is available. ([3086](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3086))
+
+#### performance
+
+- Create DebouncedValidatedTextInput component. ([3108](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3108))
+
+#### refactor
+
+- Merge ProductPrice atomic block and component. ([3065](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3065))
+
 = 3.3.0 - 2020-09-02 =
 - enhancement: Show express payment methods in the Cart block (for example: Apple Pay, Chrome Pay). [3004](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3004)
 - bug: Fix alignment of discounted prices in Cart block. [3047](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/3047)