Remove most of the old cruft that was left over from nushell version
0.87 - we are now on version 0.102!
Many of the old options are actually not helpful anymore so let's just
get rid of them entirely (never configured the shell for me too much).
Also there was a lot of 'default' commented code which made it harder to
keep an overview rather than help.
For now just set up a minimal shell experience with vi editing mode, and
the trifecta of startship prompt, zoxide movement and atuin history
enabled.
Added atuin for nice shell history. Trying it out for now
but seems non-intrusive enough that I will probably keep
it for a while even if I don't use it.
Switched terminal environments (bash,zsh,nushell) to starship
prompt (from pure-prompt/no prompt). Is mimicking the pure-
prompt however, so no big change visible. Needs additional
package on the system, which is added to the packages.
Some remaining issues with nushell (vi prompt indicator).
