After, Before are 1-Indexed Instead of 0-indexed

I would suggest a change, but this would break a lot of stuff. Therefore, I suggest changing the documentation to reflect that it's 1-indexed, as this is confusing and I thought it wasn't working (I was doing before:1 assuming it would give me the first item as a collection but it gave me nothing instead. Don't suggest "first," as I wanted a collection to run through a template and then had after:1 going through the same template)