docs(admins): add install-nix

docs/src/SUMMARY.md

@@ -22,6 +22,7 @@
 - [Install](./admins/install.md)
   - [Docker Installation](./admins/install-docker.md)
   - [Binary Installation](./admins/install-binary.md)
+  - [Nix/NixOS Installation](./admins/install-nix.md)
 - [Environments](./admins/environments.md)
 - [Create Account](./admins/create-account.md)
 

docs/src/admins/install-nix.md

@@ -0,0 +1,61 @@
+# Nix/NixOS Installation
+
+> Hatsu uses the `x86-64-v3` target architecture for optimal performance.
+>
+> If you are using an older processor, you currently need to build locally and change the corresponding values in `.cargo/config.toml`.
+
+Hatsu is available in Nixpkgs, NUR and Flakes.
+
+macOS (Darwin) is not supported.
+
+## Nixpkgs
+
+Nixpkgs only has a stable version, you need nixos-24.11 or nixos-unstable.
+
+```nix
+{ pkgs, ... }: {
+  environment.systemPackages = with pkgs; [
+    hatsu
+  ];
+}
+```
+
+## NUR (SN0WM1X)
+
+The SN0WM1X NUR may contain beta versions, but there may be a delay.
+
+You need to [follow the instructions to set up NUR](https://github.com/nix-community/nur#installation) first.
+
+```nix
+{ pkgs, ... }: {
+  environment.systemPackages = with pkgs; [
+    nur.repos.sn0wm1x.hatsu
+  ];
+}
+```
+
+## Flakes
+
+> This is untested.
+
+Add the hatsu repository directly to your flake inputs, up to date but unstable.
+
+```nix
+{
+  inputs: {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    # ...
+    hatsu.url = "github:importantimport/hatsu";
+    hatsu.inputs.nixpkgs.follows = "nixpkgs";
+    # ...
+  };
+}
+```
+
+```nix
+{ inputs, pkgs, ... }: {
+  environment.systemPackages = [
+    inputs.hatsu.packages.${pkgs.system}.default;
+  ];
+}
+```