docs: add a section on preview environment URL format (#13254)

www/apps/cloud/app/environments/preview/page.mdx

@@ -61,6 +61,18 @@ To log into the Medusa Admin of the preview environment, use the admin credentia
 
 You can also [send requests to the preview deployment's API](../../deployments/page.mdx#send-requests-to-the-deployment).
 
+### Preview URL Format
+
+Medusa generates the preview environment URL by:
+
+- Taking the first `42` characters of the PR's branch name.
+- Appending a dash (`-`) followed by the project's handle.
+    - You can find the project's handle in the project dashboard's URL, which is of the format `cloud.medusajs.com/:org_id/projects/:project_handle`.
+- Removing unsafe characters.
+- Adding the `medusajs.app` subdomain.
+
+For example, if your PR's branch name is `feat/product-review` and the project's handle is `m1234`, the URL of the deployed preview environment would be `https://featproduct-review-m1234.medusajs.app`.
+
 ---
 
 ## Open Preview Environment Dashboard

www/apps/cloud/generated/edit-dates.mjs

@@ -17,6 +17,6 @@ export const generatedEditDates = {
   "app/connect-storefront/page.mdx": "2025-06-25T07:47:00.499Z",
   "app/environments/environment-variables/page.mdx": "2025-08-15T15:35:24.085Z",
   "app/environments/long-lived/page.mdx": "2025-08-15T15:38:19.187Z",
-  "app/environments/preview/page.mdx": "2025-06-25T08:00:00.839Z",
+  "app/environments/preview/page.mdx": "2025-08-20T12:15:33.952Z",
   "app/faq/page.mdx": "2025-08-15T14:32:23.372Z"
 }