docs: added + updated build and deployment guides (#10019)

www/apps/resources/app/deployment/medusa-application/railway/page.mdx

@@ -2,7 +2,7 @@
 sidebar_label: "Railway"
 ---
 
-import { Prerequisites, DetailsList } from "docs-ui"
+import { Prerequisites } from "docs-ui"
 
 export const metadata = {
   title: `Deploy Medusa Application to Railway`,
@@ -82,6 +82,14 @@ Later, you’ll set different values of the `DISABLE_MEDUSA_ADMIN` environment v
 
 ### Configure Redis URL
 
+The `redisUrl` configuration specifies the connection URL to Redis to store the Medusa server's session.
+
+<Note>
+
+Learn more in the [Medusa Configuration documentation](/references/medusa-config#redisurl).
+
+</Note>
+
 Add the following configuration in `medusa-config.ts` :
 
 ```ts title="medusa-config.ts"