Added LIGHTNING as a possible source of damage

By: Dinnerbone <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/event/entity/EntityDamageEvent.java

@@ -150,6 +150,12 @@ public class EntityDamageEvent extends EntityEvent implements Cancellable {
          * Damage: 4 for players
          */
         VOID,
+        /**
+         * Damage caused by being struck by lightning
+         * 
+         * Damage: 5
+         */
+        LIGHTNING,
         /**
          * Custom damage.
          *