Add an example of a TS based MCP server

[rjbeers]

We should add a typescript based MCP server. It is a common scenario that uses this library.

[nickytonline]

Link to https://github.com/pomerium/mcp-app-demo and we can show where we use it. It's used in the UserContext component https://raw.githubusercontent.com/pomerium/mcp-app-demo/refs/heads/main/src/contexts/UserContext.tsx