Deployment: Dockerfile and Smithery config

[smithery-ai]

This PR adds files for deploying your MCP server on Smithery. After deployment, users can use your server over streamable HTTP (hosted on Smithery) without needing to install any dependencies.

Changes

• Added Dockerfile to package your server for deployment.
• Added Smithery Configuration file to specify how to start your server. See documentation.
• Updated README to include installation command via Smithery and a popularity badge. Note that the command only works after the server is deployed on Smithery.

Server Details

• Smithery ID: @jinzcdev/markmap-mcp-server
• Server Homepage: https://smithery.ai/server/@jinzcdev/markmap-mcp-server

Action Items

• Build Passing: We verified that the Docker builds and your server starts up using an automated test.
• Code Review: Please review the changes to ensure the configuration is accurate for your server.