No mention of 'default' filter on https://docs.bolt.cm/4.0/twig-components/filters

This page explains many Twig filters but doesn't mention the `default` filter.

The official Twig documentation page at https://twig.symfony.com/doc/3.x/filters/default.html is very helpful but it doesn't explain how an empty or missing parameter is treated, as in these constructs that I've seen in Bolt themes: `{% if record|default() %}` or `{% if record|default %}`.

So it would be good to include multiple examples, including the above.