Add lib module for modules to provide helper functions

modules/misc/lib.nix

@@ -0,0 +1,15 @@
+{ config, pkgs, ... }:
+
+{
+  options = {
+    lib = pkgs.lib.mkOption {
+      default = {};
+
+      type = pkgs.lib.types.attrsOf pkgs.lib.types.attrs;
+
+      description = ''
+        This option allows modules to define helper functions, constants, etc.
+      '';
+    };
+  };
+}

modules/module-list.nix

@@ -34,6 +34,7 @@
   ./misc/crashdump.nix
   ./misc/ids.nix
   ./misc/locate.nix
+  ./misc/lib.nix
   ./misc/nixpkgs.nix
   ./misc/passthru.nix
   ./misc/version.nix