feat: add comprehensive NixOS configuration documentation and structure

- Introduced `08-structure.md` detailing project structure, main files, and versioning.
- Created `README.md` for documentation overview and quick start guide.
- Added user-specific configurations for Alacritty, Vim, Micro, Git, Zsh, Tmux, and tools.
- Implemented system modules for desktop environment (KDE Plasma), audio (PipeWire), networking, and services (OpenSSH, GnuPG).
- Configured Nix settings with flakes support and garbage collection.
- Established user management for `ada` with necessary groups and shell settings.
- Enabled VirtualBox guest additions for improved VM experience.

nixos/modules/system/boot.nix

@@ -0,0 +1,17 @@
+{ config, lib, pkgs, ... }:
+
+{
+  # Конфигурация загрузчика
+  boot.loader.grub = {
+    enable = true;
+    device = "/dev/sda";
+    useOSProber = true;
+  };
+
+  # Параметры ядра
+  boot.kernelParams = [ "quiet" ];
+
+  # Модуль ядра AmneziaWG
+  boot.extraModulePackages = [ config.boot.kernelPackages.amneziawg ];
+  boot.kernelModules = [ "amneziawg" ];
+}