[Refactor]: Remove unnecessary nesting of app/app in root repository

[jimbrig]

Repo Structure should follow best-practices and conventions for CI/CD and other integrations and ease-of-use:

<root>/
├── app/
    ├── assets/
    ├── components/
    ├── routes/
    └── root.tsx
├── public/

not:

<root>/
├── app/
    ├── app/
        ├── assets/
        ├── components/
        ├── routes/
        └── root.tsx
    ├── public/