Homelab updates

- Change domain to opdavies.uk as this works with HTTPS/SSL.
- Switch Nginx to Caddy.

nix/hosts/nixedo/modules/acme.nix

@@ -0,0 +1,19 @@
+{ config, ... }:
+
+{
+  security.acme = {
+    acceptTerms = true;
+
+    certs = {
+      "opdavies.uk" = {
+        domain = "opdavies.uk";
+        dnsProvider = "cloudflare";
+        email = "oliver@oliverdavies.uk";
+        environmentFile = config.age.secrets.cloudflare-opdavies-uk.path;
+        webroot = null;
+
+        extraDomainNames = [ "*.opdavies.uk" ];
+      };
+    };
+  };
+}