Add grub support

[shitboox]

Normally, on NixOS, using grub is an option via boot.loader.grub attrset. However, on finix, it in fact does not seem to be. Adding grub support (back) would make dual-booting other OSes easier too, and it also has many interesting projects going for it.

[shitboox]

(also a little about myself: i found this project interesting enough so i joined github to watch it)

[aanderse]

originally i used grub with my finix laptop - i manually installed it with the cli provided. i wrote my own configuration. finix has a hook so it can integrate with anything, including the setup i mention above.

the main reason there is no automatic grub support in finix is that the configuration file in grub is very complex and not easy to manage in nix. you end up needed to write a very opinionated module for grub just like the nixos grub module. at some point maybe i will take another look at this because you are right that choice is nice.

btw limine is a very powerful boot loader that can easily dual boot multiple oses. you should take a look at it if you're interested - very cool project.