Instead of it lying in the src directory (where, reasonably, only python
data extraction, processing and modelling code should lie), I turned
the retorque filter into a simple quarto extension.
Could reasonably be repackaged separately from this repo since I believe
other people could profit off it.
Quarto 1.4 does not like a bare 'zotero' metadata frontmatter key with
sub keys for the filter options. This commit updates the zotero-live
citations filter plugin by retorque and changes its configuration so
it takes settings either through the 'zotero' key or, if that one is
not found, through the 'zoterolive' key. Same options.
