Add Nix package and NixOS moodule

Add a Scribe Nix package and NixOS module to the flake that a user can
build and install.

Includes the following supporting changes:
- Adding a name and version to package.json to make Nix's mkYarnPackage
  happy
- Update laravel-mix to fix ERR_OSSL_EVP_UNSUPPORTED on newer nodejs
  versions

module.nix

@@ -0,0 +1,111 @@
+self: { config, lib, pkgs, ... }:
+let
+  cfg = config.services.scribe;
+in
+{
+  options.services.scribe = {
+    enable = lib.mkEnableOption (lib.mdDoc "Enable or disable the Scribe service");
+
+    package = lib.mkOption {
+      type = lib.types.package;
+      default = self.packages."${pkgs.system}".default;
+      description = lib.mdDoc "Overridable attribute of the scribe package to use.";
+    };
+
+    user = lib.mkOption {
+      type = lib.types.str;
+      default = "scribe";
+      description = lib.mdDoc "User to run the Scribe service as.";
+    };
+
+    group = lib.mkOption {
+      type = lib.types.str;
+      default = "scribe";
+      description = lib.mdDoc "Group to run the Scribe service as.";
+    };
+
+    appDomain = lib.mkOption {
+      type = lib.types.str;
+      description = lib.mdDoc ''
+        The domain that Scribe is being run on. This will appear on the Scribe homepage.
+      '';
+    };
+
+    port = lib.mkOption {
+      type = lib.types.port;
+      description = lib.mdDoc "Port for the Scribe service to use.";
+    };
+
+    environmentFile = lib.mkOption {
+      type = lib.types.str;
+      description = lib.mdDoc ''
+        The path to a file containing environment varible to be set in Scribes environment.
+        This should be user to set SECRET_KEY_BASE, GITHUB_USERNAME, and GITHUB_PERSONAL_ACCESS_TOKEN. 
+        Descriptions of these settings can be found
+        [in the official docs](https://sr.ht/~edwardloveall/Scribe/#configuration).
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.scribe = {
+      description = "Scribe";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      environment = {
+        LUCKY_ENV = "production";
+        APP_DOMAIN = cfg.appDomain;
+        PORT = (toString cfg.port);
+      };
+      serviceConfig = {
+        ExecStart = "${cfg.package}/bin/scribe";
+        EnvironmentFile = cfg.environmentFile;
+        Restart = "on-failure";
+        User = cfg.user;
+        Group = cfg.group;
+        UMask = "0007";
+        ProtectSystem = "strict";
+        ProtectClock = true;
+        ProtectKernelLogs = true;
+        SystemCallArchitectures = "native";
+        ProtectHome = true;
+        ProtectProc = "noaccess";
+        MemoryDenyWriteExecute = true;
+        NoNewPrivileges = true;
+        PrivateDevices = true;
+        PrivateMounts = true;
+        PrivateTmp = true;
+        ProtectControlGroups = true;
+        ProtectHostname = true;
+        ProtectKernelModules = true;
+        ProtectKernelTunables = true;
+        RestrictNamespaces = true;
+        RestrictRealtime = true;
+        RestrictSUIDSGID = true;
+        CapabilityBoundingSet = [
+          "~CAP_SYS_PTRACE"
+          "~CAP_SYS_ADMIN"
+          "~CAP_SETGID"
+          "~CAP_SETUID"
+          "~CAP_SETPCAP"
+          "~CAP_SYS_TIME"
+          "~CAP_KILL"
+          "~CAP_SYS_PACCT"
+          "~CAP_SYS_TTY_CONFIG "
+          "~CAP_SYS_CHROOT"
+          "~CAP_SYS_BOOT"
+          "~CAP_NET_ADMIN"
+        ];
+      };
+    };
+    users.users = lib.optionalAttrs (cfg.user == "scribe") {
+      "scribe" = {
+        group = "scribe";
+        isSystemUser = true;
+      };
+    };
+    users.groups = lib.optionalAttrs (cfg.group == "scribe") {
+      "scribe" = { };
+    };
+  };
+}