updated module directory structure

modules/enable-ip-forwarding.nix

@@ -0,0 +1,12 @@
+{ config, lib, ... }:
+
+{
+  options.myNetworking.ipForwarding.enable = lib.mkEnableOption "Enable IPv4 and IPv6 forwarding";
+
+  config = lib.mkIf config.myNetworking.ipForwarding.enable {
+    boot.kernel.sysctl = {
+      "net.ipv4.ip_forward" = 1;
+      "net.ipv6.conf.all.forwarding" = 1;
+    };
+  };
+}