add core mod

modules/system/core/core.nix

@@ -0,0 +1,26 @@
+{ ... }: {
+  flake.nixosModules.core = {
+    time.timeZone = "Europe/Berlin";
+    i18n.defaultLocale = "en_US.UTF-8";
+    i18n.extraLocaleSettings = {
+      LC_ADDRESS = "de_DE.UTF-8";
+      LC_IDENTIFICATION = "de_DE.UTF-8";
+      LC_MEASUREMENT = "de_DE.UTF-8";
+      LC_MONETARY = "de_DE.UTF-8";
+      LC_NAME = "de_DE.UTF-8";
+      LC_NUMERIC = "de_DE.UTF-8";
+      LC_PAPER = "de_DE.UTF-8";
+      LC_TELEPHONE = "de_DE.UTF-8";
+      LC_TIME = "de_DE.UTF-8";
+    };
+    security = {
+      rtkit.enable = true;
+      polkit.enable = true; # polkit
+      polkit.enablePkexecWrapper = true;
+    };
+    nix.settings.experimental-features = [
+      "nix-command"
+      "flakes"
+    ];
+  };
+}