docs: fix file path in CMS integration example (#10516)

www/apps/book/app/learn/customization/integrate-systems/service/page.mdx

@@ -84,7 +84,7 @@ export const methodsHighlights = [
   ["20", "retrieveBrands", "A method that retrieves a brand from a third-party system."]
 ]
 
-```ts title="src/modules/brand/services/client.ts" highlights={methodsHighlights}
+```ts title="src/modules/cms/service.ts" highlights={methodsHighlights}
 export class BrandClient {
   // ...