Redesign README: direct structure, example tables first

[George-iam]

Summary

• Remove "What Is AXME?" intro - readers arrive already knowing the product
• Move example tables (delivery, human, internal, durability, full workflows, model-a) to the top, immediately after the header
• Add badges (Alpha status, License) and nav links to header
• Collapse repo structure, SDK versions, env vars, and related repos into a <details> block
• Add footer with contact, social, security, and license links
• All existing content preserved - reorganized only

Test plan

• Verify all section links resolve correctly in rendered markdown
• Confirm badges render (Alpha, License)
• Confirm <details> block expands correctly on GitHub
• Spot-check all tables are complete and unmodified