implement the treefmt formatter spec

[katexochen]

https://treefmt.com/latest/reference/formatter-spec/

Basically, accept files as arguments, and write change back to those files in an idempotent way.

[noperator]

@katexochen, can you try out https://github.com/noperator/jqfmt/tree/treefmt and let me know if it works for you?

[katexochen]

Thanks @noperator, that code works great and should fulfill all the treefmt formatter spec requirements. 🤩