[Feature] Add Docker Compose support for local development

[unlikelyzero]

Overview

Add Docker Compose configuration to simplify local development setup and provide containerized environment consistency for the Cypress Real World App.

Proposed Changes

• Add docker-compose.yml for orchestrating frontend and backend services
• Add Dockerfiles for frontend and backend services
• Update documentation in README.md with Docker setup instructions
• Add Docker-specific environment configuration

Technical Details

• Create Dockerfile.frontend and Dockerfile.backend using Node 22.13.0 base image
• Configure Docker Compose services:
  • Frontend service (port 3000)
  • Backend service (port 3001)
• Set up volume mounts for:
  • Source code for development
  • Data persistence (database.json)
• Add Docker-specific npm scripts for common operations

Documentation Updates

Add new section to README.md covering:

• Docker prerequisites
• Docker Compose setup instructions
• Docker-specific commands and usage
• Development workflow with Docker