added docs and fixed desc loading from item def

src/content/loading/ItemLoader.cpp

@@ -29,6 +29,7 @@ template<> void ContentUnitLoader<ItemDef>::loadUnit(
         parentDef->cloneTo(def);
     }
     root.at("caption").get(def.caption);
+    root.at("description").get(def.description);
 
     std::string iconTypeStr = "";
     root.at("icon-type").get(iconTypeStr);

src/items/ItemDef.cpp

@@ -8,6 +8,7 @@ ItemDef::ItemDef(const std::string& name) : name(name) {
 }
 void ItemDef::cloneTo(ItemDef& dst) {
     dst.caption = caption;
+    dst.description = description;
     dst.stackSize = stackSize;
     dst.generated = generated;
     std::copy(&emission[0], &emission[3], dst.emission);