Add Docker deployment support

[octaviospain]

Add Docker support to make it easier to deploy and use the Scryfall MCP Server in containerized environments.

Proposed Solution

• Multi-stage Dockerfile using distroless base for security and minimal size
• docker-compose.yml for easy deployment
• Documentation for integration with Claude Desktop and Claude Code
• Environment configuration template

Benefits

• Isolated, reproducible deployments
• No need to install Node.js or manage dependencies locally
• Easier integration with Claude Desktop/Code via Docker
• Production-ready with security best practices (non-root user, minimal attack surface)