if it's not an array, wrap it in an array. if it's already an array, do nothing.
If it's not an array, make it one:
``js
const arraywrap = require("arraywrap");
arraywrap(123); // => [123]
arraywrap("yo"); // => ['yo']
arraywrap(null); // => [null]
arraywrap(undefined); // => [undefined]
arraywrap(); // => []
`
If it's already an array, do nothing:
`js
arraywrap([1, 2, 3]); // => [1, 2, 3]
arraywrap([]); // => []
const arr = [1, 2];
arrayWrap(arr) === arr; // true
`
This supports environments that don't have Array.isArray` (like IE8 and below).