feat: (file/folder) tree layout

[xttlegendapi]

What problem are you facing?

its a bit messy and confusing now

What's the solution you'd like to see in Notesnook?

i think its better to structure it like a file tree with subfolders. the current notebook thingy UI is just too complex for what we need.

What alternatives have you considered?

No response

Additional context

No response