docs: add RustChain protocol documentation index

[antoleod]

Summary

• add a focused protocol documentation index for bounty feat: implement high-quality cross-platform miner installer script #8
• map API, consensus, attestation, epochs, hardware fingerprinting, tokenomics, glossary, and diagrams to canonical docs
• add Mermaid protocol diagrams and link them from docs/README.md

Validation

• Scanning markdown files in C:\Users\X1\Documents\mcptoolsdev.tmp\rustchain-bounty-8 for broken relative links...

✅ All relative links resolved successfully. PASS

• Building BCOS Certified Projects Directory...
  Loaded 8 projects
  Generated index.html
  Generated projects/rustchain-agent-framework.html
  Generated projects/chainguard-validator.html
  Generated projects/neural-compute-mesh.html
  Generated projects/streamcast-video-infrastructure.html
  Generated projects/agentos-runtime.html
  Generated projects/blockmesh-p2p.html
  Generated projects/rentcompute-marketplace.html
  Generated projects/videochain-encoder.html
  Build complete! Generated 9 HTML files in dist/ PASS
• PASS
• blocked locally: missing
• focused pytest blocked locally: is not installed

The original bounty issue #8 is already closed; this PR presents the documentation improvement for maintainer review.

[github-actions]

Welcome to RustChain! Thanks for your first pull request.

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• Non-doc PRs have a BCOS-L1 or BCOS-L2 label
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