treewide: format all files (#57)

Run `nix fmt` at the root of the repository to format all files. I've
done this on my fork and this will help me merge your changes later
without having to deal with un-formatted files.

config/plugins/git/lazygit.nix

@@ -1,4 +1,5 @@
-{pkgs, ...}: {
+{ pkgs, ... }:
+{
   extraPlugins = with pkgs.vimPlugins; [
     lazygit-nvim
   ];