Function shortestWord

shortestWord(str: string): string | string[]
Finds the shortest word(s) in a string.
Parameters
- str: string
  The input string.
Returns string | string[]
The shortest word as a string, or an array of tied words.
Remarks
- If only one shortest word exists, returns it as a string.
- If multiple shortest words have the same length, returns them as an array.
- Returns an empty string if there are no words.
Example
```
shortestWord("js utils kit"); // "js"
shortestWord("one three five"); // "one"
shortestWord("a ab abc abcd"); // "a"
shortestWord(""); // ""
```
- Defined in src/string/fn.ts:295