Add todo script

Signed-off-by: Oliver Davies <oliver@oliverdavies.uk>

modules/scripts/todo.nix

@@ -0,0 +1,28 @@
+{ withSystem, ... }:
+
+let
+  name = "todo";
+in
+{
+  perSystem =
+    { pkgs, ... }:
+    {
+      packages.${name} = pkgs.writeShellApplication {
+        inherit name;
+
+        runtimeInputs = with pkgs; [ coreutils ];
+
+        text = ''"$EDITOR" "$TODO_FILE"'';
+      };
+    };
+
+  flake.modules.homeManager.base =
+    { config, pkgs, ... }:
+    {
+      home.packages = [
+        (withSystem pkgs.system (psArgs: psArgs.config.packages.${name}))
+      ];
+
+      home.sessionVariables.TODO_FILE = "${config.xdg.userDirs.documents}/todo.adoc";
+    };
+}