docs: add optional Chinese core documentation

[LE0-Lin]

Summary

• Add optional Simplified and Traditional Chinese core overviews, user guides and limitation summaries, with reciprocal language selectors. English remains the default.
• Record the v0.23.0 English source revision and partial coverage. Advanced references and research documents remain English.
• Preserve executable examples, configuration, rule IDs, score limits and exit semantics. This is documentation localization, not a CLI language option or a claim about Chinese semantic detection.
• Leave runtime behavior and the already-published v0.23.0 artifacts/tag unchanged.

Validation

• 270 local unittest cases: passed, with one platform-specific skip.
• Repository self-scan passed; git diff --check passed.
• New checks verify real local links, exact English guide command parity, matching config/workflow examples, and default English package README. They do not certify translation meaning or substitute for independent human review.