Add WIP nixos config

flake.nix

@@ -0,0 +1,22 @@
+{
+  description = "Immutable NixOS dotfiles.";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+    nixpkgs-unstable.url = "nixpgs/master";
+    emacs-overlay.url = "github:nix-comunity/emacs-overlay";
+    nixos-hardwre.url = "github:nixos/nixos-hardware";
+  };
+
+  outputs = inputs @ { self, nixpkgs, ... }: {
+    nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
+      system = "x86_64-linux";
+      specialArgs = { inherit inputs; };
+      modules = [
+        ./hosts/nixos/configuration.nix
+        ./hosts/nixos/hardware.nix
+        ./config/cachix.nix
+      ];
+    };
+  };
+}

hosts/nixos/configuration.nix

@@ -0,0 +1,18 @@
+{ pkgs, ... }:
+
+{
+  nix = {
+    package = pkgs.nixUnstable;
+    extraOptions = ''
+      experimental-features = nix-command flakes
+    '';
+  };
+
+  nixpkgs = {
+    config = { allowUnfree = true; };
+    overlays = [ ];
+  };
+
+  # ...
+
+}

modules/nix.org

@@ -0,0 +1,27 @@
+#+TITLE: Nix
+#+AUTHOR: Christopher James Hayward
+#+EMAIL: chris@chrishayward.xyz
+
+#+PROPERTY: header-args:emacs-lisp :tangle nix.el :comments org
+#+PROPERTY: header-args            :results silent :eval no-export :comments org
+
+#+OPTIONS: num:nil toc:nil todo:nil tasks: nil tags:nil
+#+OPTIONS: skip:nil author:nil emacs:nil creator:nil timestamp:nil
+
+* Setup
+
+*Nix*[fn:1] is a package manager for Linux that uses functional configuration language to build reproducible package deployments. *NixOS*[fn:2] is an extension of the Nix package manager to the entire operating system.
+
+* Config
+
+Download and install ~nix-mode~ for working with *Nix* language buffers.
+
+#+begin_src emacs-lisp
+(use-package nix-mode)
+#+end_src
+
+* Footnotes
+
+[fn:1] https://nixos.org
+
+[fn:2] https://nixos.org