tuning fix + added repeats

[jackd]

This PR contains 3 main changes (probably should have been 3 PRs, but I'm not particularly fussed about whether it gets accepted or not - I'm mostly opening so that I can reference it from an issue).

• added item as per #7
• wrapped main functionality of citations_XXX in a loop and added repeats to args_XXX
• fixed errors with tuning_XXX

I've also added the results of hyperparameter tuning and --tuned runs to README.md, though there seems to be some missing seed controls to make this reproducible. Note that results are significantly worse than those reported.