Feature Request: Make cross marks available in Norinori and Heyawake.

[Stepwisecliche]

Cross marks between cells (like in Yajilin) could be an easy implementation and would help greatly with marking logic in more complex Nori and Heya puzzles. It would help in others as well, but those are the only two I can remember at the moment. A dot like in Star Battle would also suffice. Unrelated, this project is brilliant. Thank you for everything.

[x-sheep]

A list of requested types, from Discord:

Creek, Kurotto, Tapa, Nurimisaki, Aqre, Chained Block, Canal View, Coral, Cross the Streams, LITS. Edit: Paintarea, Nurimaze, Yin-Yang Maybe also: Choco Banana, Dominion, Norinuri, Stostone, Heyablock, Cocktail Lamp, Martini, all dynasty genres