Stable release

[GaetanLepage]

Since nixfmt has progressively been stabilized during the nixpkgs formatting process, I propose to make a proper stable release of it.
Also, this could be a good opportunity to apply the advertised nixfmt-rfc-style -> nixfmt rename in nixpkgs.

cc @infinisil

[khaneliman]

Some tooling has already migrated from nixfmt-rfc-style and nixfmt options to nixfmt and nixfmt-classic so it feels like it's already accepted to be transitioned that way, as well. It makes sense to start advertising it that way now after the codebase has already started to be migrated.

[infinisil]

Discussed in todays meeting:

• Blocker: Some solution for better UX, see Improving flake formatting experience #273 (comment)
• Changelog
  • RFC style
  • CLI changes
  • Speed improvements
  • Various bug fixes
  • Deprecate recursive mode again
• GitHub release
• Alias pkgs.nixfmt (currently warns, mentioning that it may use the new formatter at some point) to pkgs.nixfmt-rfc-style (or rather the other way around)

Should be able to do that in the next meeting after the blocker is resolved

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/formatting-team-meeting-2024-12-10-and-2025-01-07/58466/1