[Feature request] Process tree

**Is your feature request related to a problem? Please describe.**
Not a problem, but a tree view would be super-useful to me

**Describe the solution you'd like**
I'd like a collapsible tree view like in `htop`, but even a non-collapsible one like in `btop` would be super useful.

**Describe alternatives you've considered**
N/A

**Additional context**
N/A