Add a note regarding when @JsonPropertyDescription was added (2.3)
diff --git a/src/main/java/com/fasterxml/jackson/annotation/JsonPropertyDescription.java b/src/main/java/com/fasterxml/jackson/annotation/JsonPropertyDescription.java
index 19429e1..b039904 100644
--- a/src/main/java/com/fasterxml/jackson/annotation/JsonPropertyDescription.java
+++ b/src/main/java/com/fasterxml/jackson/annotation/JsonPropertyDescription.java
@@ -10,6 +10,8 @@
  * property.
  * Currently used to populate the description field in generated JSON
  * Schemas.
+ *
+ * @since 2.3
  */
 @Target({ElementType.ANNOTATION_TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
 @Retention(RetentionPolicy.RUNTIME)