Update README.md

Author: nielslange

packages/checkout/blocks-registry/README.md

@@ -44,7 +44,7 @@ Blocks can be registered within several different areas or parent blocks. Valid
 | `woocommerce/checkout-shipping-methods-block`    | Within the shipping methods form step.                        |
 | `woocommerce/checkout-payment-methods-block`     | Within the payment methods form step.                         |
 
-See the `innerBlockAreas` typedef for the most up to date list of available areas.
+See the [`innerBlockAreas`](https://github.com/woocommerce/woocommerce-blocks/blob/6b9955d2a51bc56b0b029edc521ff98e3403dffc/packages/checkout/blocks-registry/types.ts#L8-L33) typedef for the most up to date list of available areas.
 
 ## Registering a Block