Updated Lua Item (markdown)

Lua-Item.md

@@ -1 +1,12 @@
-PH
+Lua_Item is a class exported to Lua that represent the Item_Struct object from EQEmu.
+
+### Properties
+```
+item.null -- Returns true if this object is null
+item.valid -- Returns true if this object is not null
+```
+
+### Member Functions
+```
+Item() -- Creates a null Item
+```