Create a function that returns true if all parameters are truthy, and false otherwise.
allTruthy(true, true, true) ➞ true
allTruthy(true, false, true) ➞ false
allTruthy(5, 4, 3, 2, 1, 0) ➞ false
false, 0, "" (empty string), null, undefined, and NaN; everything else is truthy.