Move Nix files into a nix directory

Move everything from `config` to the root level.

nix/lib/wsl2/default.nix

@@ -0,0 +1,62 @@
+{
+  inputs,
+  outputs,
+  self,
+  username,
+}:
+{ system }:
+
+let
+  inherit (pkgs) lib;
+
+  pkgs = import inputs.nixpkgs {
+    overlays = [
+      outputs.overlays.additions
+      outputs.overlays.modifications
+      outputs.overlays.unstable-packages
+    ];
+  };
+
+  shared-config = import "${self}/nix/lib/shared/home-manager.nix" {
+    inherit
+      inputs
+      pkgs
+      self
+      username
+      ;
+  };
+
+  shared-packages = import "${self}/nix/lib/shared/home-manager-packages.nix" {
+    inherit inputs pkgs username;
+    desktop = false;
+  };
+in
+inputs.home-manager.lib.homeManagerConfiguration {
+  inherit pkgs;
+
+  extraSpecialArgs = {
+    inherit self;
+  };
+
+  modules = [
+    {
+      imports = [ shared-config ];
+
+      home.packages = shared-packages ++ [ pkgs.wsl-open ];
+
+      home.sessionVariables = {
+        DIRENV_LOG_FORMAT = "";
+        EDITOR = "nvim";
+        PATH = lib.concatStringsSep ":" [
+          "$PATH"
+          "$HOME/go/bin"
+          "./vendor/bin"
+          "./node_modules/.bin"
+        ];
+        PULUMI_SKIP_UPDATE_CHECK = "true";
+        REPOS = "$HOME/Code";
+        RIPGREP_CONFIG_PATH = "$HOME/.config/ripgrep/config";
+      };
+    }
+  ];
+}