Update docs for HTTP interface clients return values

See gh-30959

framework-docs/modules/ROOT/pages/integration/rest-clients.adoc

@@ -495,45 +495,76 @@ method parameters:
 [[rest-http-interface-return-values]]
 === Return Values
 
-Annotated, HTTP exchange methods support the following return values:
+The supported return values vary depending on whether you are using
+`HttpExchangeAdapter` or `ReactorHttpExchangeAdapter`.
+
+When using `HttpExchangeAdapter`, annotated HTTP exchange methods support
+the following return values:
 
 [cols="1,2", options="header"]
 |===
 | Method return value | Description
 
-| `void`, `Mono<Void>`
-| Perform the given request, and release the response content, if any.
+| `void`
+| Perform the given request.
 
-| `HttpHeaders`, `Mono<HttpHeaders>`
-| Perform the given request, release the response content, if any, and return the
-  response headers.
+| `HttpHeaders`
+| Perform the given request and return the response headers.
 
-| `<T>`, `Mono<T>`
+| `<T>`
 | Perform the given request and decode the response content to the declared return type.
 
-| `<T>`, `Flux<T>`
-| Perform the given request and decode the response content to a stream of the declared
-  element type.
+| `ResponseEntity<Void>`
+| Perform the given request and return a `ResponseEntity` with the status and headers.
 
-| `ResponseEntity<Void>`, `Mono<ResponseEntity<Void>>`
-| Perform the given request, and release the response content, if any, and return a
-  `ResponseEntity` with the status and headers.
-
-| `ResponseEntity<T>`, `Mono<ResponseEntity<T>>`
+| `ResponseEntity<T>`
 | Perform the given request, decode the response content to the declared return type, and
   return a `ResponseEntity` with the status, headers, and the decoded body.
 
+|===
+
+When using `ReactorHttpExchangeAdapter`, annotated HTTP exchange methods support
+all the same values as the ones supported by `HttpExchangeAdapter`
+and also the following ones:
+
+[cols="1,2", options="header"]
+|===
+| Method return value | Description
+
+| `Mono<Void>`
+| Perform the given request, and release the response content, if any.
+
+| `Mono<HttpHeaders>`
+| Perform the given request, release the response content, if any, and return the
+response headers.
+
+| `Mono<T>`
+| Perform the given request and decode the response content to the declared return type.
+
+| `Flux<T>`
+| Perform the given request and decode the response content to a stream of the declared
+element type.
+
+| `Mono<ResponseEntity<Void>>`
+| Perform the given request, and release the response content, if any, and return a
+`ResponseEntity` with the status and headers.
+
+| `Mono<ResponseEntity<T>>`
+| Perform the given request, decode the response content to the declared return type, and
+return a `ResponseEntity` with the status, headers, and the decoded body.
+
 | `Mono<ResponseEntity<Flux<T>>`
 | Perform the given request, decode the response content to a stream of the declared
-  element type, and return a `ResponseEntity` with the status, headers, and the decoded
-  response body stream.
+element type, and return a `ResponseEntity` with the status, headers, and the decoded
+response body stream.
 
 |===
 
 TIP: You can also use any other async or reactive types registered in the
 `ReactiveAdapterRegistry`.
 
-By default, the behavior of HTTP service methods with synchronous (blocking) method
+While using the `ReactorHttpExchangeAdapter`, by default, the behavior
+of HTTP service methods with synchronous (blocking) method
 signature depends on connection and timeout settings of the underlying HTTP client.
 `HttpServiceProxyFactory.Builder` does expose a `blockTimeout` option that also lets you
 configure the maximum time to block for a response, but we recommend configuring timeout