Agent Knowledge v0.6.3

Agent Knowledge v0.6.3 fixes and polishes the localized documentation home pages so /en/ and /zh/ are proper landing pages for readers and AI clients instead of long overview pages.

Highlights

• Converts localized index pages into proper layout: home landing pages.
• Adds clearer hero actions for the specification, quickstart, standards ecosystem, and LLM context.
• Keeps the homepage concise while routing detailed concepts to dedicated documentation pages.
• Keeps the core Agent Knowledge specification compatible with v0.6.2.