restructure

- users/rin/default.nix -> users/rin.nix
- users/rin/home.nix +-> users/rin.nix
- users/rin/*.nix -> modules/user/*.nix
- users/rin/scripts/ -> scripts/
- hosts/winter/default.nix -> hosts/winter.nix
- hosts/winter/*.nix -> modules/system/*.nix

- modules are dynamically imported as sets for system and user

modules/user/kitty.nix

@@ -0,0 +1,18 @@
+{ config, pkgs, ... }: {
+  programs.kitty = {
+    enable = true;
+    font = {
+      package = pkgs.cascadia-code;
+      name = "Cascadia Code PL";
+      size = 13;
+    };
+    settings = {
+      font_features = "-ss01 +ss19";
+      enable_audio_bell = false;
+    };
+    extraConfig = builtins.readFile (builtins.fetchurl {
+      url = "https://raw.githubusercontent.com/folke/tokyonight.nvim/main/extras/kitty_tokyonight_night.conf";
+      sha256 = "0mgjkmn4grr7rrxc5rrs1n0cghf03gp0v55hf3phll6czjavjldf";
+    });
+  };
+}