doc: update README

README.md

@@ -38,8 +38,13 @@ there are three or four:
 
 1. The programming language
 2. The build system used to compile/package the repository
-3. The Nix library/evaluation system used in the flake itself
-4. (Optional) Additional differences in project structure
+3. The Nix evaluation system used in the flake itself
+4. (Optional) Additional differences in project structure, including but not
+   limited to:
+   - `basic`: Minimal acceptable project structure
+   - `cli`: Sample CLI program
+   - `gui`: Sample GUI program
+   - `lib`: Library
 
 For example, the `python_pyproject_nixpkgs_cli` template generates a Python
 repository packaged in Pyproject format where the flake uses Nixpkgs' standard