docs: translation module (#14271)

* docs: translation module

* fix link in JS SDK

* add translations user guides [WIP]

* updates

* fix broken link

* remove mentions of default locale

* change header

* updates

* updated user guides

* handle todos

* fix build error

* fix lint errors

www/apps/resources/app/storefront-development/checkout/complete-cart/page.mdx

@@ -10,7 +10,7 @@ products:
   - payment
 ---
 
-import { CodeTabs, CodeTab } from "docs-ui"
+import { CodeTabs, CodeTab, Prerequisites } from "docs-ui"
 
 export const metadata = {
   title: `Checkout Step 5: Complete Cart`,
@@ -57,6 +57,23 @@ When the cart completion is successful, it's important to unset the cart ID from
 
 ---
 
+## Order's Locale after Cart Completion
+
+<Prerequisites
+  items={[
+    {
+      text: "Translation Module Configured",
+      link: "/commerce-modules/translation#configure-translation-module",
+    }
+  ]}
+/>
+
+When you complete the cart, items in the order will be in the locale that was set for the cart. This ensures that the customer sees the order details in their preferred language.
+
+If no locale was set for the cart, then the order's items will be in the original product content.
+
+---
+
 ## React Example with Default System Payment Provider
 
 For example, to complete the cart when the default system payment provider is used: