Adjust stair output amount

Stair recipe now outputs six stairs rather than four.

mods/stairs/init.lua

@@ -60,7 +60,7 @@ function stairs.register_stair(subname, recipeitem, groups, images, description,
 	})
 
 	minetest.register_craft({
-		output = 'stairs:stair_' .. subname .. ' 4',
+		output = 'stairs:stair_' .. subname .. ' 6',
 		recipe = {
 			{recipeitem, "", ""},
 			{recipeitem, recipeitem, ""},
@@ -70,7 +70,7 @@ function stairs.register_stair(subname, recipeitem, groups, images, description,
 
 	-- Flipped recipe for the silly minecrafters
 	minetest.register_craft({
-		output = 'stairs:stair_' .. subname .. ' 4',
+		output = 'stairs:stair_' .. subname .. ' 6',
 		recipe = {
 			{"", "", recipeitem},
 			{"", recipeitem, recipeitem},