Add choice to use alternative initramfs generators like dracut or bootster

[ArtyIF]

By default, Arch uses mkinitcpio to generate initramfs. However, some users may prefer to use alternative solutions like dracut (used by Gentoo, RHEL and Debian families of distros) or bootster. Setting them up (dracut in particular) requires some manual work (specifically creating a pacman hook to use dracut instead of mkinitcpio), and it would be a nice-to-have to automate the process on setup.

[hughesjs]

I came here to ask for dracut to be added so I second this request

[chrisemke]

It would be great to have this in archinstall