[TASK] Write Swap Relaying Documentation

[akileshtangella]

https://www.notion.so/hicommonwealth/Swaps-cdd5e2ac5b4c466ba539a4b10a9168b5?pvs=4

Expand on following topics:

• What are private swaps? Who are the parties involved (Alice, Bob, relayer).
• What role does a relayer play in private swaps?
• What information is exposed to relayer? Can the relayer steal funds?
• [ ]

Outline

• Overview
• Lifecycle (where is data moving, what is being communicated, etc.)
• Implementation Details (smart contract calls, event watching, etc.)
• Fees and Incentives
• Privacy and Security
• Links (code links, repo links, etc.)