Script for fish to use cd_on_quit feature

[nik-kita]

I make my own draft version for fish according to provided in documentation script for bash .
Copy paste it into my .config/fish/config.fish and it works... but honestly Im not sure that it is really correct and I avoid os check (Im using Ubuntu by the way)

Documentation with config => see Setting/cd_on_quit section

So may be it will be cool if mainteiners of project make this? :D
Im sure that it can be handy for fish-users.
This works for me but use it on your own risk

function spf
    set -gx SPF_LAST_DIR "$HOME/.local/state/superfile/lastdir"
    command spf $argv
    if test -f "$SPF_LAST_DIR"
        source "$SPF_LAST_DIR"
        rm -f -- "$SPF_LAST_DIR" > /dev/null
    end
end

[lazysegtree]

Created an issue - #682