cleanup whitespace and commas

* [] is now [ ]
* {} is now { }
* commas in arglists go at end of line not beginning

In short, I ran the whole thing through nixfmt-rfc-style but only
accepted about 30% of its changes. I might grow accustomed to more
of it over time

modules/squashfs.nix

@@ -1,8 +1,8 @@
 {
-  config
-, pkgs
-, lib
-, ...
+  config,
+  pkgs,
+  lib,
+  ...
 }:
 let
   inherit (pkgs) liminix;