Open links in batches

[Forage]

Thanks for creating this handy add-on.

One thing that would be useful is an option to open the links in batches of a set size. Where "1" would mean opening them one after the other and e.g. 3 would mean opening the first 3 links followed by the next 3, etc.
Some sites prevent opening too many pages at the same time.

Together with #18 it would even allow for something like opening 5 pages each minute.