replace reflection by simple use of getId method.

update Readme to add info about all entities availables.

README.md

@@ -13,11 +13,5 @@ And last but not least you can get the list of recorded zone /mobcount list
 
 In addition you have also a zone definition by having a Kelp in your principal hand and right click two block at the two coordinates.
 
-Implemented types
-
-COW
-CHICKEN
-SHEEP
-PIG
-RABBIT
-GOAT
+Implemented types: any entity by using the entity_id (e.g: cow, creeper, cat, zombie_pigman,...)
+Tips: Typing an entity that does not exist will not filtering on type and will return the full count of living entity in the zone.

src/main/java/net/mobcount/MobCountService.java

@@ -30,7 +30,7 @@ public static int mobCount(PlayerEntity player, BlockPos blockPos, BlockPos bloc
 		EntityType eType = null;
 		try
 		{
-			eType = (EntityType)EntityType.class.getField(s).get(null);
+			eType = EntityType.get(s.toLowerCase()).get();
 		}
 		catch(Exception e)
 {}