per_page Use -1/0 to return all items

Hi,
I am fiddling around with the API, and there seems to be an error in the documentation:

> per_page
> integer >= -1
>
> Amount of entries to return per page. Use -1 to return all items.

should be:

> per_page
> integer >= 0
>
> Amount of entries to return per page. Use 0 to return all items.

source: https://github.com/Kovah/LinkAce/blob/a018face013e0c5f2c6407c55e491f0d2514aad9/app/Helper/functions.php#L118
https://github.com/Kovah/LinkAce/issues/515#issuecomment-1190019571

Verify the documented behavior against app/Helper/functions.php at line 118 and the linked comment in issue 515. Locate the API reference entry for per_page, update its allowed minimum and all-items example to match the implementation, and confirm the rendered documentation shows the corrected wording.

Written by the indexing model from the issue text.