Update testing instructions

Author: opr

docs/testing/releases/590.md

@@ -2,7 +2,7 @@
 
 Zip file for testing: [woocommerce-gutenberg-products-block.zip](https://github.com/woocommerce/woocommerce-gutenberg-products-block/files/7161568/woocommerce-gutenberg-products-block.zip)
 
-## Feature plugin and package inclusion in WooCommerce
+## Feature plugin
 
 ### Add extensibility point for extensions to filter payment methods ([4668](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/4668))
 
@@ -14,14 +14,25 @@ import { registerPaymentMethodExtensionCallbacks} from '@woocommerce/blocks-regi
 registerPaymentMethodExtensionCallbacks( 'woocommerce-marketplace-extension',
 	{
 		cod: ( arg ) => { return false; },
-                 // this zipcode works only for Germany
 		cheque: ( arg ) => { return arg.billingData.city === "Denver";}
 	}
 );
 ```
 3. Go to the Checkout block
 4. Notice that Cash on delivery is no longer available
-5. Notice that Check payments are available only when the Country is Germany and the Postcode for Billing data is 12345
+5. Notice that Check payments are available only when the City is set to "Denver"
+
+## Feature plugin and package inclusion in WooCommerce
+
+### Fix Product Search block displaying incorrectly ([4740](https://github.com/woocommerce/woocommerce-gutenberg-products-block/pull/4740))
+
+1. Add the Product Search block to a page.
+2. Ensure it renders at full width with a gap between the input and the button.
+
+| Before | After |
+|---|---|
+| <img src="https://user-images.githubusercontent.com/3616980/133223981-f31f54ff-2a4d-4652-a8e8-599c7942b7ce.png" /> | ![image](https://user-images.githubusercontent.com/5656702/133245602-8751a6fd-9bad-40b2-aad0-4d91e09afdd7.png) |
+
 
 ### Smoke test the Checkout block
 Because of experimental work done during this release, we need to ensure no regressions have been made to the checkout block. Please smoke test the checkout block.