Docs: Fix return object property

[brettz9]

line is what is actually returned instead of lines.

If you wanted it to return lines, the code needs fixing (and a major version update).

[coveralls]

Coverage remained the same at 100.0% when pulling bcb212f520aba169116a96ff8931d330221c80e1 on brettz9:patch-1 into 4dea664eb6c9849d6eaf80977f72644f551f2d20 on kaesetoast:master.