update readme and add a new lucky block

lucky_block.lua

@@ -3,8 +3,9 @@ if minetest.get_modpath("lucky_block") then
 
 	lucky_block:add_blocks({
 		{"spw", "mobs:npc", 1, true, true},
+		{"spw", "mobs:igor", 1, true, true, 5, "Igor"},
 		{"spw", "mobs:trader", 1, false, false},
-		{"lig"},
+		{"lig", "fire:permanent_flame"},
 	})
 
 end

readme.md

@@ -10,4 +10,6 @@ Trader
 
 - Traders are new and still being tested but can be placed into the world using a spawn egg. Right-clicking on a trader opens his shop and allows you to buy his wares inside.  If provoked a trader will attack a player or monster.
 
-Lucky Blocks: 3
+Note: self.npc_drops and self.igor_drops are used for random item list when trading for gold and may be changed within the mob itself, if not found the global mobs.npc_drops and mobs.igor_drops are used instead for a default list.
+
+Lucky Blocks: 4