docs: fix pricing query params in storefront guide + modules restructure (#9021)

- Fix pricing query params previously using `customer_group_id` and `customer_id` as expected / accepted queries and update information around them
- Other: reorganize the introduction page of each module to show how to use it at the very beginning.

www/apps/resources/app/commerce-modules/stock-location/page.mdx

@@ -8,36 +8,6 @@ export const metadata = {
 
 The Stock Location Module is the `@medusajs/stock-location-next` NPM package that provides stock-location-related features in your Medusa and Node.js applications.
 
-## Features
-
-### Stock Location Management
-
-Store and manage stock locations. Stock locations are associated with data models of other modules that require a location, such as the [Inventory Module's InventoryLevel](../inventory/concepts/page.mdx#inventory-level).
-
-```ts
-const stockLocation = await stockLocationModuleService.createStockLocations({
-  name: "Warehouse 1",
-})
-```
-
-### Address Management
-
-Manage the address of each stock location.
-
-```ts
-const stockLocation = await stockLocationModuleService.updateStockLocations({
-  id: "sloc_123",
-  address: {
-    country_code: "us",
-    city: "New York City",
-    address_1: "52 Stone St",
-    postal_code: "10004",
-  },
-})
-```
-
----
-
 ## How to Use Stock Location Module's Service
 
 You can use the Stock Location Module's main service by resolving from the Medusa container the resource `ModuleRegistrationName.STOCK_LOCATION` imported from `@medusajs/utils`.
@@ -101,3 +71,33 @@ const step1 = createStep("step-1", async (_, { container }) => {
 
   </CodeTab>
 </CodeTabs>
+
+---
+
+## Features
+
+### Stock Location Management
+
+Store and manage stock locations. Stock locations are associated with data models of other modules that require a location, such as the [Inventory Module's InventoryLevel](../inventory/concepts/page.mdx#inventory-level).
+
+```ts
+const stockLocation = await stockLocationModuleService.createStockLocations({
+  name: "Warehouse 1",
+})
+```
+
+### Address Management
+
+Manage the address of each stock location.
+
+```ts
+const stockLocation = await stockLocationModuleService.updateStockLocations({
+  id: "sloc_123",
+  address: {
+    country_code: "us",
+    city: "New York City",
+    address_1: "52 Stone St",
+    postal_code: "10004",
+  },
+})
+```