move all expressions to nix/; include modularized home-manager config

nix/os/modules/natrouter.nix

@@ -0,0 +1,26 @@
+{ lib
+, config
+, ... }:
+with lib;                      
+
+{
+  # TODO
+  # Provide a NAT/DHCP Router
+  #
+  # networking.nat.enable = true;
+  # networking.nat.internalInterfaces = [ "enp0s20f0u4u1u3" ];
+  # networking.nat.externalInterface = "wlp1s0";
+  # networking.interfaces."enp0s20f0u4u1u3".ipv4.addresses = [
+  #     { address = "10.254.253.254"; prefixLength = 24; }
+  # ];
+  # services.dnsmasq = {
+  #   enable = true;
+  #   servers = [ "8.8.8.8" "8.8.4.4" ];
+  #   extraConfig = ''
+  #     domain=lan
+  #     interface=enp0s20f0u4u1u3
+  #     bind-interfaces
+  #     dhcp-range=10.254.253.100,10.254.253.199,1h
+  #   '';
+  # };
+}