burnham: init. defiant: add wireguard

hosts/defiant/configuration.nix

@@ -6,12 +6,15 @@
       ../../base.nix
       ../../common/metrics-exporters.nix
       ./hardware-configuration.nix
-      ./libvirt.nix
 
+      # Infrastructure
+      ./libvirt.nix
       ./services/nginx.nix
       ./services/pihole.nix
       ./services/postgresql.nix
+      ./services/wireguard.nix
 
+      # Services
       ./services/flame.nix
       ./services/gitea.nix
       ./services/hedgedoc.nix