feat: add itemsUsed field

Author: Fyrlex

src/payloads/User.ts

@@ -29,6 +29,10 @@ export interface APICountingUser<IDType = string> {
    * The total items found by the user
    */
   itemsFound: number;
+  /**
+   * The total items used by the user
+   */
+  itemsUsed: number;
   /**
    * The user's inventory
    */