Separate System and User packages

- Move user programs out of systems section and int
  user section
- Install user packages with home manager rather than
  system wide

user/development/default.nix

@@ -0,0 +1,7 @@
+{ config, lib, pkgs, ... }:
+
+{
+  imports = [
+    ./vscode.nix
+  ];
+}

user/development/vscode.nix

@@ -0,0 +1,7 @@
+{ config, lib, pkgs, ... }:
+
+{
+  home.packages = (with pkgs; [
+    vscode
+  ]);
+}