feat: add nixos and hm config

nixcfgs/modules/nixos/libvirt.nix

@@ -0,0 +1,22 @@
+{pkgs, ...}: {
+  environment.systemPackages = with pkgs; [
+    virt-manager
+  ];
+  virtualisation.libvirtd = {
+    enable = true;
+    qemu = {
+      package = pkgs.qemu_kvm;
+      runAsRoot = true;
+      swtpm.enable = true;
+      ovmf = {
+        enable = true;
+        packages = [
+          (pkgs.OVMF.override {
+            secureBoot = true;
+            tpmSupport = true;
+          }).fd
+        ];
+      };
+    };
+  };
+}