Add pianonix, create modules and augment others

modules/nixos/locales/default.nix

@@ -0,0 +1,47 @@
+{
+  # Snowfall Lib provides a customized `lib` instance with access to your flake's library
+  # as well as the libraries available from your flake's inputs.
+  lib,
+  # An instance of `pkgs` with your overlays and packages applied is also available.
+  pkgs,
+  # You also have access to your flake's inputs.
+  inputs,
+
+  # Additional metadata is provided by Snowfall Lib.
+  namespace, # The namespace used for your flake, defaulting to "internal" if not set.
+  system, # The system architecture for this host (eg. `x86_64-linux`).
+  target, # The Snowfall Lib target for this system (eg. `x86_64-iso`).
+  format, # A normalized name for the system target (eg. `iso`).
+  virtual, # A boolean to determine whether this system is a virtual target using nixos-generators.
+  systems, # An attribute map of your defined hosts.
+
+  # All other arguments come from the module system.
+  config,
+  ...
+}:
+
+let
+  cfg = config.modules.locales;
+in
+{
+  options.modules.locales = {
+    enable = lib.mkOption { default = false; };
+  };
+
+  config = lib.mkIf cfg.enable {
+    # Select internationalisation properties.
+    i18n.defaultLocale = "en_US.UTF-8";
+
+    i18n.extraLocaleSettings = {
+      LC_ADDRESS = "de_DE.UTF-8";
+      LC_IDENTIFICATION = "de_DE.UTF-8";
+      LC_MEASUREMENT = "de_DE.UTF-8";
+      LC_MONETARY = "de_DE.UTF-8";
+      LC_NAME = "de_DE.UTF-8";
+      LC_NUMERIC = "en_US.UTF-8";
+      LC_PAPER = "de_DE.UTF-8";
+      LC_TELEPHONE = "de_DE.UTF-8";
+      LC_TIME = "de_DE.UTF-8";
+    };
+  };
+}