Fix and document Nix

[astrale-sharp]

To any nix fans out there, It's been reported on the discord that it might not be working, if someone can fix and document it, it would be appreciated <3

[NorfairKing]

Some input here:

https://github.com/astrale-sharp/typstfmt/commit/a9e6249019111783380be88390e86af3441076ab#commitcomment-126176318

[astrale-sharp]

Can you tell me if last version 37796887ff0bcad2c03a14642a707e5a205f6533 works with nix?

[NorfairKing]

@astrale-sharp that seems to work!

[astrale-sharp]

Nice! Thanks!