Title: Add a product

Primary Actor: Seller

Precondition: Seller logged in to main page.

Main Scenario:

1. The app presents a button to add a product named "Add Product"
2. Seller clicks the button
3. The app opens a form with details to enter for the product.
4. Seller enters details for the product like Name, Price, and how many they have available.
5. Seller clicks on the submit button to add the product
6. The app confirms that a product with the name is added.

Extensions:

4a. Seller also uploads an image for the product

6a. The product name already exists

6a1. The app warns that a product with the name already exists.

6b. Seller clicks cancel

6b1. The app takes the seller back to main page without adding the product.