Update upgrade-to-v8.adoc

docs/upgrade-to-v8.adoc

@@ -28,13 +28,14 @@ Furthermore, RESTHeart 8 configures Undertow to use its `ThreadAwareByteBufferPo
 The following options manage virtual threads:
 
 ```yaml
-# Specifies the initial number of platform carrier threads used for virtual threads in blocking operations.
-# Recommended value: 1.5 * number of cores.
-# If <= 0, it defaults to 1.5 times the system core count.
-workers-scheduler-parallelism: 0
-
-# Sets the maximum number of platform carrier threads for virtual threads in blocking operations.
-workers-scheduler-max-pool-size: 256
+core:
+  # Specifies the initial number of platform carrier threads used for virtual threads in blocking operations.
+  # Recommended value: 1.5 * number of cores.
+  # If <= 0, it defaults to 1.5 times the system core count.
+  workers-scheduler-parallelism: 0
+
+  # Sets the maximum number of platform carrier threads for virtual threads in blocking operations.
+  workers-scheduler-max-pool-size: 256
 ```
 
 == Cookie Authentication
@@ -324,4 +325,4 @@ public abstract T parseContent() throws IOException, BadRequestException;
 
 `ServiceRequest.parseContent()` is called by `ServiceRequest.getContent()` on its first invocation. The parsed content is then cached and linked to the request, ensuring that any subsequent calls will reuse the already parsed content object.
 
-This approach makes handling request content more efficient by reducing unnecessary parsing and processing overhead.
+This approach makes handling request content more efficient by reducing unnecessary parsing and processing overhead.