also refactor nixos modules

modules/nixos/services/persistance/postgresql.nix

@@ -0,0 +1,30 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  inherit (lib) mkIf mkEnableOption;
+
+  cfg = config.sneeuwvlok.services.persistance.postgresql;
+in {
+  options.sneeuwvlok.services.persistance.postgresql = {
+    enable = mkEnableOption "Postgresql";
+  };
+
+  # Access db with `psql -U postgres`
+  config = mkIf cfg.enable {
+    services = {
+      postgresql = {
+        enable = true;
+        authentication = ''
+          # Generated file, do not edit!
+          # TYPE  DATABASE  USER  ADDRESS       METHOD
+          local   all       all                 trust
+          host    all       all   127.0.0.1/32  trust
+          host    all       all   ::1/128       trust
+        '';
+      };
+    };
+  };
+}