## Summary
- replace the unsupported `data-var-*` example with the current `data-variable-values` pattern
- document that variable values are carried through but still applied manually inside the nested composition
- add matching reference notes in the data-attributes, HTML schema, core package, and CLI docs
## Verification
- `npx mintlify dev --port 3100`
- browser verification with `agent-browser` on `/concepts/compositions` and `/reference/html-schema`
- proof artifacts saved locally under `tmp/issue-416-docs/`
Major improvements across all 18 pages:
- Use Mintlify components: <Steps> for tutorials, <Tabs> for alternatives,
<CodeGroup> for multi-platform commands, <Tree> for directory structures,
<AccordionGroup> for FAQ/scannable content, <Mermaid> for diagrams
- Add filename annotations to all code blocks (e.g., ```html index.html)
- Add numbered comments inside multi-step code examples
- Show expected terminal output after CLI commands
- Add "When to use" / "When NOT to use" sections to all package pages
- Add "Next Steps" CardGroup to every page (no dead-end pages)
- Cross-link between pages at point of curiosity (not just "see also" dumps)
- Expand thin pages (engine, studio) with architecture details and examples
- Add decision guides (rendering modes, template selection)
- Use <Warning> and <Note> sparingly (max 2-3 per page)
Also adds DOCS_GUIDELINES.md at repo root with writing standards.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
ukimsanov