Add emem geospatial MCP example

[vortx-jaya]

Hi AutoGen team,

We added an AutoGen example for emem, a remote MCP server for signed geospatial facts and place-based verification.

Example:
https://github.com/Vortx-AI/emem/tree/main/examples/autogen

emem MCP endpoint:
https://emem.dev/mcp

emem MCP Registry:
io.github.Vortx-AI/emem

The example uses McpWorkbench with StreamableHttpServerParams to connect an AutoGen assistant to emem and run a geospatial verification question about Helsinki Airport, Finland.

Would you be open to linking this from the AutoGen MCP examples/docs, or should we open a PR adding it directly?