I've added automatic checking of discarded cards to ensure that they match a built train link. Adding the same checking for stations is a future item. Please let me know if you find anything that does not work. I've testing it, but something might have slipped through.

- When tunnels are selected, three cards are automatically put into the tunnel check zone.
- At the end of each turn, cards in the tunnel check and discard area zones are moved to the discard deck.

Changes from original mod by Mitty:
- Moved placement of discard piles
- Shuffle and replace draw deck when it's empty instead of less than 6 cards
- Button to draw 3 cards for checking tunnels
- Rotate cards as they enter your hand