feat: add thatsme MCP server

[ThatsMeADM]

Adds thatsme MCP server (thatsme-mcp-issuer on npm).

thatsme is a digital certificate issuance platform — the world's
first RewardTech. This server enables AI agents to issue 3D digital
certificates, query engagement analytics, and export data via the
thatsme API.

npm: https://www.npmjs.com/package/thatsme-mcp-issuer

[olaservo]

Thanks for contributing to the MCP servers repo!

Per CONTRIBUTING.md, this repo no longer accepts new server implementations — the src/ tree is reserved for a small set of reference servers that illustrate MCP protocol features.

The right home for new servers is the MCP Registry, where they can be discovered by users and clients:

• Quickstart: https://github.com/modelcontextprotocol/registry/blob/main/docs/modelcontextprotocol-io/quickstart.mdx
• Browse: https://registry.modelcontextprotocol.io/

Closing this PR accordingly, but we appreciate you building on MCP — please publish to the Registry!

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Note: I'm working through the backlog with help from Claude Code to give everyone a prompt response.