add emacs

emacs.nix

@@ -0,0 +1,22 @@
+{ lib, config, ... }:
+let cfg = config.cos.emacs; in
+{
+  options.cos.emacs = {
+    enable = lib.mkEnableOption "emacs";
+    org-directory = lib.mkOption {
+      type = lib.types.str;
+      default = "~/org";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    home-manager.users.${config.cos.username} = {pkgs, ...}: {
+      programs.emacs = {
+        enable = true;
+        extraConfig = ''
+          (setq package-archives nil)
+        '';
+      };
+    };
+  };
+}