Specify start record for using the shortcode

[mjellings]

I would like to be able to specify which record to start at when using the shortcode, this is essentially so I can use the shortcode multiple times to achieve something similar to:

Latest publications
Shortcode here, use the limit to select only 1 record

Previous publications
Shortcode here, use a 'skip' parameter to say you want to start at the 2nd record

I'll look at modifying the code and send over a pull request when I can.

Thanks