Commands: sell buy shop shops

Some rooms have shops in them. You will see them on their own line
in the room's description. In general, if there is only one shop in
a room, you can omit the shop name at the end of the command.

View shops in the room:
[ ] > shops

List items in a shop:
[ ] > shops list shop name
[ ] > shop list

View an item in a shop:
[ ] > shops show item from shop name
[ ] > shop show item

Buy an item from a shop:
[ ] > buy item from shop name
[ ] > buy item

Sell an item to a shop:
[ ] > sell item to shop name
[ ] > sell item

When matching a shop name, you can use the shortest unique string for
the shop. So "Blacksmith" can be matched with "blac".