Update coding-agents lab to use ported mcp server

[vedubhat]

Currently, the Coding Agents Lab uses a TypeScript-based MCP server. Since the ported MCP server has been released, the Coding Agents Lab README needs to be updated to use the ported MCP server.

• Update documentation site by adding a new page for specmatic MCP
• Test the ported MCP server with coding-agents lab to make sure it works as expected.
• Raise a PR and get it approved.