Update menu.js - Streamline add cart process (#16)

Modified the existing code to store the saved items in an array to
streamline the process @Anjaliavv51
#5

menu.js

@@ -8,9 +8,16 @@ document.addEventListener('DOMContentLoaded', function () {
                 var itemName = item.querySelector('h3').textContent;
                 var itemPrice = item.querySelector('p').textContent;
                 alert("Item added to cart successfully");
+
+                // Retrieve existing cart items from localStorage
+                var cartItems = JSON.parse(localStorage.getItem('cartItems')) || [];
+
+                // Add new item to the cart array
+                var newItem = { name: itemName, price: itemPrice };
+                cartItems.push(newItem);
 
-                localStorage.setItem('itemName', itemName);
-                localStorage.setItem('itemPrice', itemPrice);
+                // Save updated cart back to localStorage
+                localStorage.setItem('cartItems', JSON.stringify(cartItems));
 
                 window.location.href = "cart.html";
             }