Document automatic context propagation

Closes gh-35689

Author: sdeleuze

framework-docs/modules/ROOT/pages/languages/kotlin/coroutines.adoc

@@ -264,9 +264,11 @@ The {spring-framework-api-kdoc}/spring-core/org.springframework.core/-propagatio
 {micrometer-context-propagation-docs}/[Micrometer Context Propagation library] works with Kotlin Coroutines.
 
 It requires the `io.micrometer:context-propagation` dependency and optionally the
-`org.jetbrains.kotlinx:kotlinx-coroutines-reactor` one.
+`org.jetbrains.kotlinx:kotlinx-coroutines-reactor` one. Automatic context propagation via
+`CoroutinesUtils#invokeSuspendingFunction` (used by Spring to adapt Coroutines to Reactor `Flux` or `Mono`) can be
+enabled by invoking `Hooks.enableAutomaticContextPropagation()`.
 
-Applications can then use the `PropagationContextElement` to augment the `CoroutineContext`
+Applications can also use `PropagationContextElement` explicitly to augment the `CoroutineContext`
 with the context propagation mechanism:
 
 include-code::./ContextPropagationSample[tag=context,indent=0]

framework-docs/src/main/kotlin/org/springframework/docs/languages/kotlin/coroutines/propagation/ContextPropagationSample.kt

@@ -34,12 +34,12 @@ class ContextPropagationSample {
 	// tag::context[]
 	fun main() {
 		runBlocking(Dispatchers.IO + PropagationContextElement()) {
-			suspendingFunction()
+			waitAndLog()
 		}
 	}
 
-	suspend fun suspendingFunction() {
-		delay(1)
+	suspend fun waitAndLog() {
+		delay(10)
 		logger.info("Suspending function with traceId")
 	}
 	// end::context[]