docs: add OKF section to LLM Wiki technologies

[jasen215]

Summary

Add a Standards & Formats section (section 2) to the LLM Wiki Technologies page (EN + ZH):

• OKF v0.1 (Open Knowledge Format) — Google Cloud's engineering spec for the LLM Wiki idea. KB = Markdown files + YAML frontmatter. WikiLoop bundles are OKF-conformant.
• YAML frontmatter schema — knowledge unit identity card fields
• Knowledge unit + relations — Markdown links over folder hierarchy, forming a navigable agent knowledge map

Test plan

• Local pnpm docs:build passes
• Confirm https://jasen215.github.io/wikiloop/ecosystem/llm-wiki-technologies shows the new section after merge