Migrate to App Router (Next.js) and others...

https://mdxjs.com/
https://nextjs.org/docs/app

The Next.js App Router is a new paradigm for building applications using React's latest features. If you're already familiar with Next.js, you'll find that the App Router is a natural evolution of the existing file-system based router in the Pages Router.

1. migrate to app router
2. removed unused dependencies
3. reverted to npm <- from pnpm
4. purged unused components and media
5. convert all blogs,projects and anothers to MDX
6. create a new page about guestbook
7. in the guestbook page adding google auth