Add support for programs.delta module

[phucleeuwu]

Description

The delta program is a syntax-highlighting pager for git, diff, and grep. Currently, Home Manager does not provide a programs.delta module, and attempting to enable it results in the following error:

error: The option `home-manager.users.<user>.programs.delta' does not exist.

While delta can be installed manually via:

home.packages = [ pkgs.delta ];

having a dedicated module would improve usability and consistency with other CLI tools like git and bat.

Expected Behavior

A programs.delta module should be available with an option like:

programs.delta.enable = true;

which would automatically install delta and possibly allow configuration of its settings.

Additional Context

• Home Manager Version: (output of home-manager --version)
• Nixpkgs Version: (output of nix-instantiate --eval --expr '<nixpkgs>')
• System: (e.g., macOS/Darwin or Linux)

Would love to see this implemented! Thanks for the great work. 🚀

[mathjiajia]

use programs.git.delta.enable

see https://nix-community.github.io/home-manager/options.xhtml

[phucleeuwu]

use programs.git.delta.enable

see nix-community.github.io/home-manager/options.xhtml

I know but I no module file name git.delta.nix. So I have to config in git.nix. I want to separate delta config and git config