common: move to modules, move some files out, modules: adjust dir structure

modules/nixos/system/home-manager.nix

@@ -0,0 +1,18 @@
+{ inputs, config, ... }:
+
+{
+  imports = [ inputs.home-manager.nixosModules.home-manager ];
+  
+  home-manager = {
+    useGlobalPkgs = true;
+    useUserPackages = true;
+    backupFileExtension = "bak";
+    extraSpecialArgs = { inherit inputs; };
+    users.wo2w = {
+      home = {
+        username = "wo2w";
+        homeDirectory = "/home/wo2w";
+      };
+    };
+  };
+}