docs: revise admin customization pages (medusajs#10466)

* docs: revise admin customization pages

* fix prerequisites link

* apply lint

www/apps/book/app/learn/advanced-development/data-models/check-constraints/page.mdx

@@ -29,12 +29,12 @@ export const checks1Highlights = [
 ```ts highlights={checks1Highlights}
 import { model } from "@medusajs/framework/utils"
 
-const CustomProduct = model.define('custom_product', {
+const CustomProduct = model.define("custom_product", {
   // ...
   price: model.bigNumber(),
 })
 .checks([
-  (columns) => `${columns.price} >= 0`
+  (columns) => `${columns.price} >= 0`,
 ])
 ```
 
@@ -53,15 +53,15 @@ export const checks2Highlights = [
 ```ts highlights={checks2Highlights}
 import { model } from "@medusajs/framework/utils"
 
-const CustomProduct = model.define('custom_product', {
+const CustomProduct = model.define("custom_product", {
   // ...
   price: model.bigNumber(),
 })
 .checks([
   {
-    name: 'custom_product_price_check',
-    expression: (columns) => `${columns.price} >= 0`
-  }
+    name: "custom_product_price_check",
+    expression: (columns) => `${columns.price} >= 0`,
+  },
 ])
 ```
 

www/apps/book/app/learn/advanced-development/data-models/relationships/page.mdx

@@ -152,7 +152,7 @@ const Order = model.define("order", {
     mappedBy: "orders",
     pivotTable: "order_product",
     joinColumn: "order_id",
-    inverseJoinColumn: "product_id"
+    inverseJoinColumn: "product_id",
   }),
 })
 

www/apps/book/app/learn/advanced-development/workflows/compensation-function/page.mdx

@@ -236,7 +236,7 @@ const step1 = createStep(
     )
 
     return new StepResponse(ids, prevData)
-  },
+  }
 )
 ```
 

www/apps/book/app/learn/customization/custom-features/api-route/page.mdx

@@ -97,7 +97,7 @@ You create a validation schema in a TypeScript or JavaScript file under a sub-di
 import { z } from "zod"
 
 export const PostAdminCreateBrand = z.object({
-  name: z.string()
+  name: z.string(),
 })
 ```
 

www/apps/book/app/learn/customization/customize-admin/page.mdx

@@ -1,10 +1,23 @@
 export const metadata = {
-  title: `${pageNumber} Customize Admin to Add Brands`,
+  title: `${pageNumber} Customize Medusa Admin Dashboard`,
 }
 
 # {metadata.title}
 
-In the next chapters, you'll continue with the brands example to learn how to customize the Medusa Admin to:
+In the previous chapters, you've customized your Medusa application to [add brands](../custom-features/module/page.mdx), [expose an API route to create brands](../custom-features/api-route/page.mdx), and [linked brands to products](../extend-features/define-link/page.mdx).
 
-- Show a product's brand on its details page using a widget.
-- Add a page showing the list of brands in your application using a UI route.
+After customizing and extending your application with new features, you may need to provide an interface for admin users to utilize these features. The Medusa Admin dashboard is extendable, allowing you to:
+
+- Insert components, called [widgets](../../advanced-development/admin/widgets/page.mdx), on existing pages.
+- Add new pages, called [UI Routes](../../advanced-development/admin/ui-routes/page.mdx).
+
+From these customizations, you can send requests to custom API routes, allowing admin users to manage custom resources on the dashboard
+
+---
+
+## Next Chapters: View Brands in Dashboard 
+
+In the next chapters, you'll continue with the brands example to:
+
+- Add a new section to the product details page that shows the product's brand.
+- Add a new page in the dashboard that shows all brands in the store.