[......] insert-at-index
insert a value, or an array, into an array at an index
usage
yarn add insert-at-index
npm i insert-at-index --save
const insertAt = require('insert-at-index')
examples
const list = [0, 1, 2, 3, 4]
const eh = ['canada', 'moose']
insertAt(list, 2, eh)
console.log(list)