Readme update

[mmurad2]

• improve copy upfront (value prop)
• make 'how it works' section more concise (less duplicative of technical report)
• add updated demo video
• fix nav

[mmurad2]

Copy.of.MCP.mp4

Ordering.task.mp4

Repo.Milestone.Trigger.-.Final.demo.mp4

[mmurad2]

Ordering.task.1.mp4