docs: add routing page (#9550)

- Add a new homepage to `book` project for the routing page
- Move all main doc pages to be under `/v2/learn` (and added redirects + fixed links across docs)
- Other: add admin components to resources dropdown + fixes to search on mobile.

Closes DX-955

Preview: https://docs-v2-git-docs-router-page-medusajs.vercel.app/v2

www/apps/resources/app/recipes/oms/page.mdx

@@ -43,13 +43,13 @@ For example, you can support importing orders into Medusa through a custom API R
     icon: AcademicCapSolid,
   },
   {
-    href: "!docs!/basics/api-routes",
+    href: "!docs!/learn/basics/api-routes",
     title: "Create API Route",
     text: "Learn how to create a custom API Route.",
     icon: AcademicCapSolid,
   },
   {
-    href: "!docs!/basics/scheduled-jobs",
+    href: "!docs!/learn/basics/scheduled-jobs",
     title: "Create Scheduled Jobs",
     text: "Learn how to create a scheduled job.",
     icon: AcademicCapSolid,
@@ -82,7 +82,7 @@ Emitting of event `order.fulfillment_created` isn't implemented yet.
     icon: AcademicCapSolid,
   },
   {
-    href: "!docs!/basics/events-and-subscribers",
+    href: "!docs!/learn/basics/events-and-subscribers",
     title: "Create a Subscriber",
     text: "Learn about create a subscriber",
     icon: AcademicCapSolid,
@@ -111,7 +111,7 @@ Emitting of event `order.payment_captured` isn't implemented yet.
     icon: AcademicCapSolid,
   },
   {
-    href: "!docs!/basics/events-and-subscribers",
+    href: "!docs!/learn/basics/events-and-subscribers",
     title: "Create a Subscriber",
     text: "Learn about create a subscriber",
     icon: AcademicCapSolid,
@@ -179,7 +179,7 @@ Emitting of event `order.return_requested` isn't implemented yet.
     icon: AcademicCapSolid,
   },
   {
-    href: "!docs!/basics/events-and-subscribers",
+    href: "!docs!/learn/basics/events-and-subscribers",
     title: "Create a Subscriber",
     text: "Learn about create a subscriber",
     icon: AcademicCapSolid,