Solution 1
https://stackoverflow.com/questions/39927452/recursively-print-all-permutations-of-a-string-javascript
Solution 2
https://www.reddit.com/r/javascript/comments/5fjbgy/recursion_in_javascript_to_find_permutations_of_a/
Solution 3
https://medium.com/@lindagmorales94/how-to-solve-a-string-permutation-problem-using-javascript-95ad5c388219
Solution 4