fix: use Array<T> syntax consistently in exercises

- Changed array type annotation from `Product[]` to `Array<Product>` in class basics problem

This ensures consistency between problem hints and solutions, reducing learner confusion.

Author: kentcdodds

exercises/01.classes/01.problem.class-basics/index.ts

@@ -6,7 +6,7 @@
 // - Method: getDescription() returns "Product: {name} - ${price}"
 
 // 🐨 Create a ShoppingCart class with:
-// - Field: items (Product[])
+// - Field: items (Array<Product>)
 // - Constructor to initialize empty items array
 // - Method: addItem(product: Product) adds to items
 // - Method: getTotal() returns sum of all product prices