9. As a user, I want to mark an item on my shopping list as purchased so the app can learn how often I buy different items

[fullybaked]

Summary

Users need a UI that allows them to mark the their items as purchased, so they can track what on their list they do and do not need to buy.

Acceptance criteria

• The ListItem component renders a checkbox with a semantic <label>.
• Checking off the item in the UI also updates the dateLastPurchased and totalPurchases properties on the corresponding Firestore document
• The item is shown as checked for 24 hours after the purchase is made (i.e. we assume the user does not need to buy the item again for at least 1 day). After 24 hours, the item unchecks itself so the user can buy it again.
• The updateItem function in firebase.js has been filled out, and sends updates to the firestore database when an item is checked

Notes:

• While you will need to update multiple parts of the Firestore document for this feature, do not worry about dateNextPurchased yet. That will be addressed in a future issue.
• You can use the Firestore console to test that this feature is working correctly, e.g., by manipulating the value of dateLastPurchased