meta: Add configuration.nix

These are my first steps towards using Nix and NixOS to declaratively
configure a reasonably good development environment. I am aware that
there are various paradigms that include using home manager and/or
flakes, however I am still exploring with a simple configuration.nix.

configuration.nix

@@ -0,0 +1,78 @@
+{ config, pkgs, lib, ... }:
+
+{
+  imports = [./hardware-configuration.nix];
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+
+  networking.hostName = "nixos";
+  networking.networkmanager.enable = true;
+
+  programs.fish.enable = true;
+  users.defaultUserShell = pkgs.fish;
+  environment.shells = with pkgs; [ fish ];
+
+  time.timeZone = "America/New_York";
+
+  i18n.defaultLocale = "en_US.UTF-8";
+  i18n.supportedLocales = ["en_US.UTF-8/UTF-8" "ja_JP.UTF-8/UTF-8" "fr_FR.UTF-8/UTF-8"];
+
+  services.xserver.enable = true;
+  services.xserver.desktopManager.gnome.enable = true;
+  services.xserver.displayManager.gdm.enable = true;
+  programs.thunar.enable = true;
+
+  nix.package = pkgs.nixFlakes;
+  nix.settings.experimental-features = ["nix-command" "flakes"];
+  environment.systemPackages = with pkgs; [
+    neovim
+    tmux
+    fish
+    wget
+    librewolf
+    kitty
+    mullvad-vpn
+    mullvad-browser
+    papirus-icon-theme
+    alacritty
+    pywal
+    mpv
+    neofetch
+    anki
+    git
+    home-manager
+    hyprland
+    htop
+    logseq
+    wl-clipboard
+  ];
+
+  fonts.enableDefaultFonts = true;
+  fonts.fonts = with pkgs; [
+    noto-fonts
+    noto-fonts-cjk
+    noto-fonts-emoji
+    hack-font
+  ];
+
+  fonts.fontconfig = {
+    defaultFonts = {
+      serif = ["Noto Serif CJK JP" "Noto Serif"];
+      sansSerif = ["Noto Sans CJK JP" "Noto Sans"];
+      monospace = ["Noto Mono CJK JP" "Noto Mono"];
+    };
+  };
+
+  fonts.fontconfig.hinting.style = "hintfull";
+
+  i18n.inputMethod = {
+    enabled = "ibus";
+    ibus.engines = with pkgs.ibus-engines; [ anthy mozc ];
+  };
+
+  services.gnome.core-utilities.enable = false;
+  services.mullvad-vpn.enable = true;
+
+  system.stateVersion = "22.11";
+}