bustabit median helper function

median.js

engine.median = function (span) {
	let arr = engine.history.slice(0, (span ? Math.max(1, Math.min(50, span)) : 50)).map(a => a.bust).sort((a, b) => { return a - b })
	let mid = arr.length / 2, med = mid % 1 ? arr[mid - 0.5] : (arr[mid - 1] + arr[mid]) / 2;
	return med;
};

// Example Usage
log(`Last 25 Bust Median: ${engine.median(25)}`);
log(`Last 50 Bust Median: ${engine.median()}`);