Site restructure

[Pelsin]

Site restructure

This PR aims to separate large portions of what actually is docs aimed on the firmware and information around it such as how to contribute or downloads information.

The size of this PR really grew, decided to limit the scope to this. So there is still three things that should be moved outside versioned documentation and that is:

• Getting help/Support
• FAQ
• Controller building

New navbar

• Removed "home"
• Renamed "Get Started" to "Documentation"
• Added logos for discord and github
• The version dropdown is only shown under documentation
• Mobile support

Desktop

Mobile

Download

• No longer versioned
• The url/path has been changed from https://gp2040-ce.info/downloads/download-page -> https://gp2040-ce.info/downloads
• All duplicate assets have been removed from versioning

Contribute / Development

• No longer versioned

Readme

• Removed all duplicates and versioned ones, now only using the generated one from the main repo

Updated tons of dependencies

Used as reference:
https://docusaurus.io/
https://reactnative.dev/
https://jestjs.io/