chore: reorganize docs apps (#7228)

* reorganize docs apps

* add README

* fix directory

* add condition for old docs

www/apps/resources/app/commerce-modules/order/concepts/page.mdx

@@ -0,0 +1,51 @@
+export const metadata = {
+  title: `Order Concepts`,
+}
+
+# {metadata.title}
+
+In this document, you’ll learn about orders and their general fields.
+
+## Order Data Model
+
+An order represents a customer purchase in your store. The `Order` data model holds the information about that purchase.
+
+---
+
+## Order Items
+
+The items purchased in the order are represented by the `OrderItem` data model. An order can have multiple items.
+
+![https://res.cloudinary.com/dza7lstvk/image/upload/v1712304722/Medusa%20Resources/order-order-items_uvckxd.jpg](https://res.cloudinary.com/dza7lstvk/image/upload/v1712304722/Medusa%20Resources/order-order-items_uvckxd.jpg)
+
+Learn more about order items in [this guide](../order-items/page.mdx).
+
+---
+
+## Order’s Shipping Method
+
+An order has one or more shipping methods used to handle item shipment. Each shipping method is represented by the `ShippingMethod` data model that holds its details.
+
+### data Field
+
+When fulfilling the order, you may use a third-party fulfillment provider that requires additional custom data to be passed along from the order creation process.
+
+The `ShippingMethod` data model has a `data` field. It’s an object used to store custom data relevant later for fulfillment.
+
+In the Medusa application, the `data` is passed to the Fulfillment Module when fulfilling items.
+
+---
+
+## Order Totals
+
+The order’s total amounts (including tax total, total after an item is returned, etc…) are represented by the `OrderSummary` data model. An order can have multiple summaries.
+
+---
+
+## Order Payments
+
+Payments made on an order, whether they’re capture or refund payments, are recorded as transactions represented by the `Transaction` data model.
+
+An order can have multiple transactions. The sum of these transactions must be equal to the order summary’s total. Otherwise, there’s an outstanding amount.
+
+Learn more about transactions in [this guide](../transactions/page.mdx).