Add OISD-nsfw blocklist

[orrinwitt]

You already have the main OISD blocklist as an option, but it does not include all the domains in their nsfw list.

Is there a way to add this list manually, or could we get it added to the list of options?

Perhaps for some of these well-known, reputable sources with multiple lists, we could have a drop-down list with checkboxes or something like that?