docs, cli: enforce package-bound docs, add template scaffolding, and document CLI usage

- Restrict mkdocstrings generation to real Python packages (require __init__.py)
- Add explicit documentation section for CLI scaffolding and templates
- Generalize CLI to support multiple templates with dynamic discovery
- Package templates correctly for importlib.resources access
- Add fully documented health_app template (app entry point and handlers)
- Fix setuptools package-data configuration for bundled templates

These changes make documentation import-safe, clarify package boundaries,
and provide a deterministic, OpenAPI-first scaffolding workflow via CLI.

pyproject.toml

@@ -84,7 +84,7 @@ Versions = "https://git.aetoskia.com/aetos/openapi-first/tags"
 packages = { find = { include = ["openapi_first*"] } }
 
 [tool.setuptools.package-data]
-fastapi_openapi_first = ["templates/**/*"]
+openapi_first = ["templates/**/*"]
 
 
 [tool.ruff]