Convert home-manager to flakes

Instead of calling the home manager directly in the user's list, we add
a command for the user to invoke "hms" and have their environment setup
in the way that Greg likes.

hosts/jude/boot.nix

@@ -4,6 +4,12 @@
 	# Use the systemd-boot EFI boot loader.
 	#boot.loader.systemd-boot.enable = true;
 	boot.loader.grub.device = "/dev/nvme0n1";
+	boot.loader.grub.useOSProber = true;
+	boot.loader.grub.extraEntries = ''
+		menuentry "Windows" {
+		  chainloader (hd0,2)+1
+		}
+	'';
 	boot.loader.efi.canTouchEfiVariables = true;
 	networking.interfaces.enp4s0.useDHCP = true;
 }