How my Python distributions are packaged — MolSSI cookiecutter-cms pyproject layout (setuptools build backend, dynamic version, optional-dependencies, console scripts) and the monorepo pattern: many sub-distributions under one umbrella sharing a PEP 420 `mkt` namespace (no top-level `__init__.py`), each with its own pyproject.toml and a `graft`-ing MANIFEST.in. Use when adding a package or sub-package, wiring entry points/package data, or debugging what does/doesn't get installed.
