docs: change config snippets to use defineConfig (#7546)

www/apps/resources/app/commerce-modules/payment/module-options/page.mdx

@@ -104,31 +104,32 @@ When the Medusa application starts, these providers are registered and can be us
 For example:
 
 ```js title="medusa-config.js"
-const modules = {
+const { Modules } = require("@medusajs/modules-sdk")
+
+// ...
+
+module.exports = defineConfig({
   // ...
-  payment: {
-    resolve: "@medusajs/payment",
-    options: {
-      providers: [
-        {
-          resolve: "@medusajs/payment-stripe",
-          options: {
-            // ...
+  modules: {
+    [Modules.PAYMENT]: {
+      resolve: "@medusajs/payment",
+      options: {
+        providers: [
+          {
+            resolve: "@medusajs/payment-stripe",
+            options: {
+              // ...
+            },
           },
-        },
-        {
-          resolve: "medusa-payment-paypal",
-          options: {
-            // ...
-          },
-        },
-      ],
+        ],
+      },
     },
-  },
-}
+  }
+})
 ```
 
 The `providers` option is an array of objects that accept the following properties:
 
-- `resolve`: A string indicating the package name of the payment provider module or the payment plugin, or the path to the file defining the payment provider.
-- `options`: An optional object of options to pass to the payment provider.
+- `resolve`: A string indicating the package name of the payment provider module or the path to it relative to the `src` directory.
+- `options`: An optional object of the payment provider module's options. The object must have the following property:
+  - `config`: An object whose key is the ID of the payment provider, and its value is an object of options to pass to the provider module.

www/apps/resources/app/commerce-modules/payment/page.mdx

@@ -72,26 +72,6 @@ await paymentModuleService.processEvent({
 
 ## Configure Payment Module
 
-To use the Payment Module, enable it in the `modules` object in `medusa-config.js`:
-
-```js title="medusa-config.js"
-const { Modules } = require("@medusajs/modules-sdk")
-
-// ...
-
-const modules = {
-  // ...
-  [Modules.PAYMENT]: {
-    resolve: "@medusajs/payment",
-    options: {
-      // ...
-    },
-  },
-}
-```
-
-### Module Options
-
 Refer to [this documentation](./module-options/page.mdx) for details on the module's options.
 
 ---

www/apps/resources/app/commerce-modules/payment/payment-provider/stripe/page.mdx

@@ -39,30 +39,36 @@ npm install @medusajs/payment-stripe
 Next, add the module to the array of providers passed to the Payment Module:
 
 ```js title="medusa-config.js"
-const modules = {
+const { Modules } = require("@medusajs/modules-sdk")
+
+// ...
+
+module.exports = defineConfig({
   // ...
-  payment: {
-    resolve: "@medusajs/payment",
-    options: {
-      providers: [
-        {
-          resolve: "@medusajs/payment-stripe",
-          options: {
-            config: {
-              stripe: {
-                credentials: {
-                  usd: {
-                    apiKey: process.env.STRIPE_USD_API_KEY,
+  modules: {
+    [Modules.PAYMENT]: {
+      resolve: "@medusajs/payment",
+      options: {
+        providers: [
+          {
+            resolve: "@medusajs/payment-stripe",
+            options: {
+              config: {
+                stripe: {
+                  credentials: {
+                    usd: {
+                      apiKey: process.env.STRIPE_USD_API_KEY,
+                    },
                   },
-                },
+                }
               }
-            }
+            },
           },
-        },
-      ],
+        ],
+      },
     },
-  },
-}
+  }
+})
 ```
 
 ### Environment Variables