Typo in queen attack exercise in Prolog track

PR: Fix small grammar error in queen attack exercise by aage · Pull Request #247 · exercism/prolog · GitHub

Yeah that doesn’t look right, although instructions to most practice exercises are from the problem spec repo, so I recommend opening a pr there.
Link to the file: problem-specifications/description.md at main · exercism/problem-specifications · GitHub

Hey @Meatball, thank you, I’ll have a look asap.