There is too much in the App component

[TuenDeBuis]

As described by the official React documentation, you should split up your application/UI into a component hierarchy.
As of commit 653e21d, the App.tsx file is reaching 730 lines of code on the main branch.
This means that it has become unwieldy and hard to work with.
I suggest breaking things up into a better component hierarchy.
This might even help with performance improvements (#39) as components are only rerendered when their props/state dictates.