Swagger UI code comes from: https://github.com/swagger-api/swagger-ui.
Usage:
rust
let doc_url = "/openapi.json";
let app = Router::new()
.nest("/swagger-ui", SwaggerUi::setup(doc_url))
.route(doc_url, get(openapi_spec_handler))
// your other routes
.route("/", get(|| async { "Hello, World!" }));