Add a function that truncates a string

[sosmaniac-FCC]

Thank you Kent for creating this tutorial environment. May I work on a function that truncates a string?
Inspiration: https://stackoverflow.com/questions/1301512/truncate-a-string-straight-javascript
Something along the lines of:

function (target, length) {
    // return the string parameter 'target' truncated by the amount of the integer parameter 'length'
}

[kentcdodds]

Sounds super! 👍