docs: update admin extension docs (#4778)

* docs: update admin extension docs

* eslint fixes

* fix broken links

* fix broken link

* added admin upgrade guide

* fix lint errors

www/docs/content/admin/routes.md

@@ -2,9 +2,6 @@
 title: 'How to Create an Admin UI Route'
 description: 'Learn how to create a new route in the admin dashboard.'
 addHowToData: true
-badge:
-  variant: orange
-  text: beta
 ---
 
 In this document, you’ll learn how to create a new route in the admin dashboard.
@@ -29,12 +26,6 @@ If you want to create a page under the Settings page, please refer to [this docu
 
 It’s assumed you already have a Medusa backend with the admin plugin installed before you move forward with this guide. If not, you can follow [this documentation page](../create-medusa-app.mdx) to install a Medusa project.
 
-Furthermore, Admin UI Routes are currently available as a beta feature. So, you must install the `beta` version of the `@medusajs/admin` and `@medusajs/medusa` packages:
-
-```bash npm2yarn
-npm install @medusajs/admin@beta @medusajs/medusa@beta
-```
-
 ### (Optional) TypeScript Preparations
 
 Since routes are React components, they should be written in `.tsx` or `.jsx` files. If you’re using Typescript, you need to make some adjustments to avoid Typescript errors in your Admin files.
@@ -190,7 +181,7 @@ For example:
 ```tsx
 import { Post } from "../../../../../models/post"
 import PostForm from "../../../../components/post/form"
-import { RouteProps } from "@medusajs/admin-ui"
+import { RouteProps } from "@medusajs/admin"
 
 const BlogPostCreatePage = ({
   notify,