Review Suggested Edit

Repeat the characters [FINALIZED]

Given a string and a non-negative integer $n$, output a new string in which each character is repeated $n$ times.

Test cases:
```
"abc", 1    -> "abc"
"Hello", 0  -> ""
"double", 2 -> "ddoouubbllee"
"Hi", 4     -> "HHHHiiii"
"", 20      -> ""
```