Expose `short_citation` option

[stefanv]

The template.yml doesn't currently expose the short_citation option. This would be quite useful to me, since the auto-citation calls me "Walt` instead of "Van der Walt".

[rowanc1]

We should also carry through the logic on name parsing, we did do some work on this on the TS side, but I think are only passing the string-name through and the logic is not present in typst.