SPIGOT-3609: Add additional notes to PlayerInteractAtEntityEvent

By: md_5 <git@md-5.net>

paper-api/src/main/java/org/bukkit/event/player/PlayerInteractAtEntityEvent.java

@@ -9,6 +9,9 @@ import org.bukkit.util.Vector;
 /**
  * Represents an event that is called when a player right clicks an entity that
  * also contains the location where the entity was clicked.
+ * <br>
+ * Note that the client may sometimes spuriously send this packet in addition to {@link PlayerInteractEntityEvent}.
+ * Users are advised to listen to this (parent) class unless specifically required.
  */
 public class PlayerInteractAtEntityEvent extends PlayerInteractEntityEvent {
     private static final HandlerList handlers = new HandlerList();