Implement Initial Setup

This is a first implementation of the Initial Setup.
Everything is already functional but there are definitely places to refine and cleanup.

TODO:

• Automated Switching between MainWindow and SetupWindow
• Setup Path Invalidation

Enhancements:

• Code Cleanup
• Validate the Gist's owner on Authentication
• Fade in Navigation Buttons

Showcase (old):
2024-05-03_23-28-53