docs: improved cart documentation (#2027)

docs/content/advanced/storefront/how-to-implement-checkout-flow.mdx

@@ -18,6 +18,8 @@ It’s recommended to go through the [Shipping Architecture Overview](../backend
 
 This document assumes you’ve already taken care of the add-to-cart flow. So, you should have a [cart created](https://docs.medusajs.com/api/store/cart/create-a-cart) for the customer with at least [one product in it](https://docs.medusajs.com/api/store/cart/add-a-line-item).
 
+You can learn how to implement the cart flow using [this documentation](../../guides/carts-in-medusa.mdx).
+
 To follow along with this tutorial, you can make use of the [Medusa JS Client](https://www.npmjs.com/package/@medusajs/medusa-js). You can install it with this command:
 
 ```bash npm2yarn
@@ -325,5 +327,6 @@ If the order is placed successfully, you can access the order data in `response.
 
 ## What’s Next 🚀
 
+- Learn more about the [JS Client and how to use it](../../js-client/overview.md).
 - Check out available plugins for popular payment providers such as [Stripe](../../add-plugins/stripe.md) and [PayPal](/add-plugins/paypal.md).
 - Learn more about the [Payment](../backend/payment/overview.md) and [Shipping](../backend/shipping/overview.md) Architectures.