Start urwid with the right colormode

[geier]

Urwid supports multiple color modes (256 colors, truecolor, possibly more). We Currently start in truecolor mode, but it makes sense to check what the current terminal supports and choose the right color mode.

We might want to get inspired by how neovim chooses what colormode to use.

[syasma]

hi, i am a junior devlopper and i want to work on this issue. How can i do ?