Fill documentation gaps: tutorials, template author guide, and architecture diagram #149
Description
Summary
The documentation scaffolding (#136) created placeholder pages, but key content is still missing. Several reference docs exist, but how-to guides are stubs and there is no architecture overview.
Scope
Priority 1: Getting-started tutorial
A complete walkthrough for first-time users: install, run, answer prompts, inspect output. Should cover uvx cookieplone for the common case.
Priority 2: Template author guide
How to create a new template, use computed fields, add validators, structure sub-templates, and test locally.
Priority 3: Architecture diagram
A visual overview of the data flow: CLI → repository resolution → config/state (v1/v2 schemas) → wizard (tui-forms) → generator (cookiecutter) → hooks. This helps both contributors and template authors understand where their code fits.
Acceptance criteria
- Getting-started tutorial is complete and renders correctly
- Template author guide covers schema v2, computed fields, validators, and sub-templates
- Architecture diagram (Mermaid or similar) added to concepts section
- All new docs pass
make docs-valelinting