chore: reorganise nix files into base dir

modules/applications.nix

@@ -0,0 +1,23 @@
+{ config, lib, pkgs, ... }:
+
+{
+  environment.systemPackages = with pkgs; [
+    gimp
+    audacity
+    obsidian
+    element-desktop
+    thunderbird
+  ];
+
+  programs.kdeconnect.enable = true;
+  systemd.user.services.kdeconnectd = {
+    enable = true;
+    after = [ "network.target" ];
+    wantedBy = [ "default.target" ];
+    description = "kdeconnectd";
+    serviceConfig = {
+        Type = "simple";
+        ExecStart = "${pkgs.kdePackages.kdeconnect-kde}/libexec/kdeconnectd";
+    };
+  };
+}