sequenceDiagram Links

In searching through the docs and trying this out it seems that many of the diagrams support both anchor and JS "links." However, I can't find how to add a link to sequenceDiagram. Basically I want a sequenceDiagram to have one or more clickable links to static pages.

Are links already implemented for sequenceDiagram? If so what are the basics and I'll do a PR to add this to the docs?

If links are not part of sequenceDiagrams do you expect this to be difficult to add and if I wanted to PR this in which file would I first poke around to make this change?

Thanks.