Add rescue mode script

[h8d13]

This morning I deleted sudo by accident playing around with --noconfirm scripts. Specifically wanted to build a parser that would support same format as -r requirements.txt but for pacman and it went wrong in the -Rns category lol.

Anyways I thought it would be good to have a utility that can save your ass from ISO or other install. Obviously isn't perfect but I tried to re-use as much as possible from existing menus. And it showed my root partition selected it ran pacman -S sudo, rebooted and was done.

[svartkanin]

We had some form of "helper" scripts before with swiss.py which was supposed to be more for dev. It is extremely painful to maintain and keep up to date and I'm not to keen on getting back into that as it's extremely time sonsuming with limited testing options.

This seems more like a personal thing to hack around and I'm not sure there's much value including it into the repo itself

[h8d13]

I think it would be invaluable. The amount of times i see people on forums saying "just re-install". Just because they do not have a mount/chroot script. This would explicitly makes that available.

I do see the issue with maintaining, but if we re-use from the code-base as much as possible and simply use arch-chroot it kinda updates itself. It's also why you made this structure if I'm not mistaken scripts are supposed to help also manage existing installations.

Just wanted to show a PoC that actually helped me fix my stuff, so yes personal, but hell why not?