Finish this shopping app by adding code to calculate the total cost of the items. You can assume any price for your items. Add more items to make it a useful shopping app. Look at the sample item - the Party hat on how to add the count next to Make the Empty Cart button work - all item counts go to 0 when it is clicked. Extra challenge: Ask the user to enter the sales tax in their area, and use that in your total cost calculations.
