Alacritty terminal emulator is now enabled with custom settings for window opacity, padding, font, and colors. Updated Git userName and userEmail to Zephrynis, and added a new shell alias 'update-laptop' for rebuilding NixOS on the laptop.
Add a NixOS system configuration using flakes, supporting multiple hosts (desktop, laptop, my-machine) with shared and per-host settings. Includes Home Manager integration, user-level and system-level package management, and example hardware configuration placeholders. Provides a README with setup instructions and a .gitignore for common Nix and editor artifacts.
