Add Initial Code Setup Instructions for X-Plane, Relay, and iMotions

Description

Enhance the README file by including step-by-step setup instructions for X-Plane, Relay, and (if possible) iMotions, ensuring easier onboarding for new contributors

Tasks

• Add setup instructions for X-Plane (plugin installation, IP config, etc.).
• Add setup steps for Relay (build and run instructions).
• Include instructions for connecting to iMotions (if supported) or Use Mock Server.
• Validate all steps in a clean environment to ensure reproducibility.

Acceptance Criteria

• README contains clear setup sections for each component (X-Plane, Relay, iMotions).
• All setup steps are verified and functional.
• A first-time contributor can complete the full setup (X-Plane → Relay → iMotions/Mock Server) in under 30 minutes using only the README.