nixos: profiles: move from top-level

My profiles are actually just "special" NixOS modules in that they
orchestrate settings that usually span the NixOS/home-manager boundary,
or otherwise set up configurations from multiple modules at once.

modules/nixos/profiles/wm/default.nix

@@ -0,0 +1,29 @@
+{ config, lib, ... }:
+let
+  cfg = config.my.profiles.wm;
+in
+{
+  options.my.profiles.wm = with lib; {
+    windowManager = mkOption {
+      type = with types; nullOr (enum [ "i3" ]);
+      default = null;
+      example = "i3";
+      description = "Which window manager to use";
+    };
+  };
+
+  config = lib.mkMerge [
+    (lib.mkIf (cfg.windowManager == "i3") {
+      # Enable i3
+      services.xserver.windowManager.i3.enable = true;
+      # i3 settings
+      my.home.wm.windowManager = "i3";
+      # Screenshot tool
+      my.home.flameshot.enable = true;
+      # Auto disk mounter
+      my.home.udiskie.enable = true;
+      # udiskie fails if it can't find this dbus service
+      services.udisks2.enable = true;
+    })
+  ];
+}