Function randomElementWeightedSource

randomElementWeightedSource<V>(
    array: ArrayLike<V>,
    weightings: number[],
    randomSource?: RandomSource,
): () => V
Selects a random array index, biased by the provided weightings.

In the below example, a will be picked 20% of the time, b 50% and so on.
```
const data =    [  `a`,  `b`,  `c`,  `d` ]
const weights = [ 0.2,  0.5,  0.1,  0.2 ] 
```
Type Parameters
- V
Parameters
- array: ArrayLike<V>
- weightings: number[]
- randomSource: RandomSource = Math.random
Returns () => V