make equippedentity serializeable

src/entity/item/mod.rs

@@ -217,7 +217,7 @@ impl InventoryItemEntity {
     }
 }
 
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize)]
 pub struct EquippedEntity {
     pub weapon: Option<ItemEntityId>,
     pub armor: Option<ItemEntityId>,