Normalizes a number from another range into a value between 0 and 1. Identical to map(value, low, high, 0, 1).
Numbers outside of the range are not clamped to 0 and 1, because out-of-range values are often intentional and useful. (See the second example above.)
float value = 20; float n = norm(value, 0, 50); println(n); // Prints "0.4"