input: Write a python function to simulate a purchasing process that collects user information and prints a purchase summary.
  assert purchase_item(['John Doe', '123 Elm St', 'Laptop', '2']) == "Thank you for your order!\nName: John Doe\nAddress: 123 Elm St\nItem: Laptop, Quantity: 2"
  assert purchase_item(['Jane Smith', '456 Oak St', 'Book', '1']) == "Thank you for your order!\nName: Jane Smith\nAddress: 456 Oak St\nItem: Book, Quantity: 1"
output: def purchase_item(details):
      name, address, item, quantity = details
      return f"Thank you for your order!\nName: {name}\nAddress: {address}\nItem: {item}, Quantity: {quantity}"