add several application, delete old generations, newer kernel

modules/packages.nix

@@ -20,6 +20,9 @@
     atomix # puzzle game
   ]);
 
+  # disable xterm
+  services.xserver.excludePackages = [ pkgs.xterm ]; 
+
   # packages in global env
   environment.systemPackages = with pkgs; [
     # system utilities
@@ -39,5 +42,12 @@
     # multimedia
     vlc
     gimp
+
+    # file transfer
+    warp
+
+    # gui utilities
+    pdfarranger
+    diebahn
   ];
 }