feat: add antd doc <component> command to output full markdown docs

Bundle raw markdown content (doc/docZh) in component data during
extraction, and expose it via a new `doc` command. This complements
`antd info` by providing the complete unprocessed API documentation
for cases where structured prop extraction is insufficient.

- src/types.ts: Add `doc` and `docZh` optional fields to ComponentData
- scripts/extract.ts: Bundle raw markdown (frontmatter-stripped) into each component during extraction
- src/commands/doc.ts: New command — outputs markdown or JSON, with error handling and fuzzy match suggestions
- src/index.ts: Register the new doc command
- data/v5.json, data/v5.29.3.json: Re-extracted with doc/docZh fields

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: afc163