Docs: Add README and System Architecture Documentation

[mgaditya-er]

Summary

Added comprehensive project documentation for the TaskTracker backend application.

Changes

README

• Added project overview
• Added tech stack details
• Added project structure
• Added setup and installation steps
• Added environment variable configuration
• Added application run instructions
• Added testing and coverage commands
• Added API endpoint documentation
• Added future enhancement roadmap

Architecture Documentation

• Added high-level architecture diagram
• Documented application layers
• Documented request flow
• Added database design and relationships
• Added logging architecture
• Added middleware architecture
• Added deployment architecture for future scalability

Benefits

• Easier onboarding for new developers
• Clear understanding of system design
• Standardized project documentation
• Better maintainability and knowledge sharing

Validation

• Documentation reviewed
• Folder structure verified
• Markdown formatting validated

Files Added

• README.md
• docs/architecture.md