Nix flake

[valyntyler]

Added nix flake to project for improved reproducibility and future integration with nixpkgs.

[SohelIslamImran]

Thanks. I really appreciate your work. @valyntyler

But sorry! I'm not familiar with Nix Flake. Can you please explain

1. What is Nix flake?
2. Why we need it?
3. What are the benefits of using it?

I just built this as a fun project. I don't want to add any complexity. Ghostty is already adding this animation
with a command built into the terminal ghostty-org/ghostty#4876

I think most people have a node and they just can run it. And this isn't a command people use on a daily basis. I'm seeing people are not using it! and after ghostty will officially adds this to the terminal, people will even no longer use it. So it was a fun project, I have no intention of add any more complexity.

[valyntyler]

Hi! I use NixOS and wanted to package your app as a fun project. It is not strictly necessary for your app to have a flake. The main reason you'd want one is for better integration with the greater nix ecosystem. I'm glad to hear your app is getting merged into ghostty. Merging this would allow your app to be easily run with nix run, as well as making it compatible with the nix package manager (I opened this PR because I wanted to try your animation out and noticed that it wasn't available in nixpkgs). I totally understand if you would prefer not to merge, but I personally believe this doesn't add any additional complexity to the project (it just integrates its features better) and I don't think you'd ever have to think about this code again regardless