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

pkgs/write-fennel-script/default.nix

@@ -1,5 +1,3 @@
-{ writeFennel
-, stdenv
-}:
-name : packages : source :
+{ writeFennel, stdenv }:
+name: packages: source:
 writeFennel name { inherit packages; } source