Some suggestions

[danielgerigk]

Hello Daniel,

as you said "Pull requests [...] are very much welcome!", here they come ...

1. the "clojure.set" library is not used anywhere,
2. the visual representation of the board could be improved ( - but, of course, this is subject to personal taste - ),
3. as it stands, it is possible for the user to move a peg from position a to position b, even if there is no peg at position a.

Best, Daniel Gerigk

[ferrucc-io]

I found that without removing the clojure.set library the program crashes, so this PR is needed!