**What - what changes are in this PR**
Typo on the homepage in the codeTabs
**Why - why are these changes relevant**
Simple typo that might be bothering more people than just me!
**How - how have the changes been implemented**
Fixed the typo from: `notificaitonModuleService` to `notificationModuleService`
**Testing - how has the changes been tested or how can the reviewer test the feature**
Should be simple enough not to require full testing locally!
- 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
