Initial NixOS flake-based multi-host setup

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.

hosts/desktop/configuration.nix

@@ -0,0 +1,63 @@
+{ config, pkgs, ... }:
+
+{
+  # Desktop PC specific configuration
+  
+  networking.hostName = "desktop";
+
+  # Users configuration
+  users.users.yourusername = { # Change "yourusername" to your actual username
+    isNormalUser = true;
+    description = "Your Name"; # Change this
+    extraGroups = [ "networkmanager" "wheel" "video" "audio" ];
+    shell = pkgs.zsh; # or pkgs.bash
+  };
+
+  # Enable zsh system-wide
+  programs.zsh.enable = true;
+
+  # Display manager and desktop environment / window manager
+  services.xserver = {
+    enable = true;
+    
+    # Display manager
+    displayManager.gdm.enable = true;
+    
+    # Desktop environment (choose one, or comment all for a standalone WM)
+    # desktopManager.gnome.enable = true;
+    # desktopManager.plasma5.enable = true;
+    
+    # Window manager (uncomment if you want a standalone WM)
+    # windowManager.i3.enable = true;
+    # windowManager.bspwm.enable = true;
+  };
+
+  # Optional: Enable Wayland compositor
+  # programs.hyprland = {
+  #   enable = true;
+  #   xwayland.enable = true;
+  # };
+
+  # Desktop-specific packages (gaming, streaming, etc.)
+  environment.systemPackages = with pkgs; [
+    # Add desktop-specific packages here
+    # discord
+    # steam
+    # obs-studio
+  ];
+
+  # Gaming support (uncomment if needed)
+  # programs.steam.enable = true;
+  # programs.gamemode.enable = true;
+
+  # Fonts
+  fonts.packages = with pkgs; [
+    noto-fonts
+    noto-fonts-cjk-sans
+    noto-fonts-emoji
+    liberation_ttf
+    fira-code
+    fira-code-symbols
+    (nerdfonts.override { fonts = [ "FiraCode" "JetBrainsMono" "Iosevka" ]; })
+  ];
+}