Update Javadoc for TestInstancePreDestroyCallback regarding scope

Author: sbrannen

junit-jupiter-api/src/main/java/org/junit/jupiter/api/extension/TestInstancePreDestroyCallback.java

@@ -23,7 +23,14 @@
  * the test instance, invoking custom clean-up methods on the test instance, etc.
  *
  * <p>Extensions that implement {@code TestInstancePreDestroyCallback} must be
- * registered at the class level.
+ * registered at the class level if the test class is configured with
+ * {@link org.junit.jupiter.api.TestInstance.Lifecycle @TestInstance(Lifecycle.PER_CLASS)}
+ * semantics. If the test class is configured with
+ * {@link org.junit.jupiter.api.TestInstance.Lifecycle @TestInstance(Lifecycle.PER_METHOD)}
+ * semantics, {@code TestInstancePreDestroyCallback} extensions may be registered
+ * at the class level or at the method level. In the latter case, the
+ * {@code TestInstancePreDestroyCallback} extension will only be applied to the
+ * test method for which it is registered.
  *
  * <h3>Constructor Requirements</h3>
  *