Function abbreviate

abbreviate(text?, width?, placeholder?): string | undefined | null
Returns a string that abbreviates the given text using placeholder
Parameters
- Optionaltext: null | string
  the text to inspect
- width: number = -1
  the max width of the expected string
- placeholder: string = '...'
  the placeholder to append
Returns string | undefined | null
a string that abbreviates the given text using placeholder
Example
```
abbreviate('foobar', -1);    // 'foobar'
abbreviate('foobar', 0);    // ''
abbreviate('foobar', 5);    // 'fo...'
abbreviate('foobar', 6);    // 'foobar'
abbreviate('foobar', 10);    // 'foobar'
```