Four-letter-blocks

Polish the sets of puzzles packed together and printed on Game Crafter (37). Start work on puzzle pairs (26).

See the full list of changes on the [milestone].

[milestone]: https://github.com/donkirkby/four-letter-blocks/milestone/2?closed=1

Pack pieces together and draw both sides, to print on Game Crafter, for 23. Also add several warnings for puzzle construction.

Group clues by adding a suit to each corner (10). Also change font size and export with transparent background (12).

Basic features: create the grid, write the clues, and split up into blocks of four letters.