Twigify the oxford comma
Twig's `|join` filter can accept two arguments: "glue" and "and". This means for the developer you can add a separator for just the last two items, and finally achieve your dream of enforcing the oxford comma within generated content.
The usage does appear inscrutable when applied here:
{{ items|join(', ',', and') }}
{# outputs: Peter, Bjorn, and John #}