Flip strings.split
For example:
```nickel
- split "1,2,3" "," =>
+ split "," "1,2,3" =>
[ "1", "2", "3" ]
- split "1,2,3" "." =>
+ split "." "1,2,3" =>
[ "1,2,3" ]
```
"#m
- = fun s sep => %strSplit% s sep,
+ = fun sep s => %strSplit% s sep,
trim : Str -> Str
| doc m#"
