Add zfs and acme module

modules/acme.nix

@@ -0,0 +1,21 @@
+{ config, lib, ... }:
+
+let
+  cfg = config.security.acme;
+in
+{
+  options.security.acme.staging = lib.mkOption {
+    type = lib.types.bool;
+    default = false;
+    description = lib.mdDoc ''
+      If set to true, use Let's Encrypt's staging environment instead of the production one.
+      The staging environment has much higher rate limits but does not generate fully signed certificates.
+      This is great for testing when the normla rate limit is hit fast and impacts other people on the same IP.
+      See <literal>https://letsencrypt.org/docs/staging-environment</literal> for more detail.
+    '';
+  };
+
+  config = lib.mkIf cfg.staging {
+    security.acme.server = "https://acme-staging-v02.api.letsencrypt.org/directory";
+  };
+}

modules/zfs.nix

@@ -0,0 +1,12 @@
+{ config, lib, ... }:
+
+let
+  cfg = config.boot.zfs;
+in
+{
+  config = lib.mkIf cfg.enabled {
+    boot.kernelPackages = config.boot.zfs.package.latestCompatibleLinuxPackages;
+
+    services.zfs.autoScrub.enable = true;
+  };
+}