add user conf and split some configs

modules/system/user.nix

@@ -0,0 +1,23 @@
+{ pkgs, username, ... }: {
+  users = {
+    users."${username}" = {
+      linger = true;
+      isNormalUser = true;
+      description = "${username}";
+      initialPassword = "${username}";
+      shell = pkgs.zsh;
+      extraGroups = [
+        "networkmanager"
+        "wheel"
+        "dialout"
+        "libvirtd"
+        "docker"
+        "input"
+        "uinput"
+        "ydotool"
+        "adbusers"
+        "kvm"
+      ];
+    };
+  };
+}