Add comprehensive Rustdoc comments for `place_prediction`. Document parameters, the prediction cooldown mechanism, stake limits enforcement, referral handling, fee deduction flow, emitted events (PredictionPlaced), and all possible error conditions.
Add comprehensive Rustdoc comments for
place_prediction. Document parameters, the prediction cooldown mechanism, stake limits enforcement, referral handling, fee deduction flow, emitted events (PredictionPlaced), and all possible error conditions.