Shop List
This screen shows a list of the shops. You may change the name of a shop,
add a new one or delete it (all shopping items assigned to the shop
will be changed or deleted accordingly).
Selecting a shop in the list will show you the shopping items assigned to this shop.
Shops are an optional feature. You do not have to assign your shopping items to a shop.
On the right side of the list the number of open items and of checked-off items (in parenthesis) is shown.
On the left side a bar is shown with the color of the highest priority of items in the shop.