nixify

[harryprayiv]

This is a friendly attempt at nixifying this useful little app to allow it to work most anywhere one would be building nixos.

edit: Other than removing this pull request and submitting it again without personalization, I am not sure how to clean this up. Sorry about that.

[thefossguy]

I mean to look at this soon. Out for FOSDEM.

[thefossguy]

Hey sorry about the delay. This completely went off my radar.

This is actually great work!

I recommend the following commit structure:

1. The first commit should be just the source rewrite to Bash. Instead of putting all Bash code in the flake file, create a separate script that can be run independently from a devShell.
2. Second commit should include changes to the derivation to build the rewrite.
3. Bump version just once. We didn't release anything so no need to bump twice (0.2.0 -> 0.3.0 then again 0.3.0 -> 0.4.0). Just bump it to 0.3.0.
4. Please rename the PR title to 'Rewrite in Bash'.
5. Update the README.