A small suggestion: instead of just puzzle.md and solution.md, it'd be nice to have hint.md or even hint1.md, hint2.md, and so on. Right now your options are ei

A small suggestion: instead of just puzzle.md and solution.md, it'd be nice to have hint.md or even hint1.md, hint2.md, and so on. Right now your options are either solve it completely yourself or have the answer given to you, and providing various levels of hints help people get some of the enjoyment of solving it even if they don't have that initial eureka moment.