[REQ][cpp-pistache-server] Support generation of swagger-ui alongside the Server

Is your feature request related to a problem? Please describe.

When generating a server from an OpenAPI spec it would be very useful to also have the ability to run swagger UI under a subpath of the API such as /docs.

Describe the solution you'd like

I'd like to have an option available that allows to generate a swagger-ui under a configurable path.

Describe alternatives you've considered

Hosting swagger-ui externally and pointing to the service works okayish, but having it run alongside the API would work a lot easier.

Additional context

There's the mention of Documentation Feature within the docs, but I cannot find more detail on it and if this is somehow related to this request.

Start with docs/generators/cpp-pistache-server.md, especially its Documentation Feature section, and compare that description with the cpp-pistache-server generator behavior. Identify how a configurable documentation subpath would fit alongside the generated server, then determine the generator tests and templates that would need coverage; done means the option produces usable Swagger UI at the selected path.