add tree command

nixos/default.nix

@@ -54,6 +54,7 @@
     e2fsprogs    # disk format utilities, like mkfs.ext4
     bat          # Like cat, but with syntax highlighting
     openssl      # Used to generate certs, random strings, etc
+    tree         # CLI directory display software
   ];
 
   # Select internationalisation properties.

wallpapers

@@ -1 +1 @@
-Subproject commit 1de3f3a19978f0b00ede6670c5027497a43beea8
+Subproject commit dc1085957c1750128f3c607cc2d480f0d183de56