Given a YAML field name, find the (R) Markdown files that contain this field
and its value contains any of the specified values. Functions
find_tags()
and find_categories()
are wrappers of
find_yaml()
with field = 'tags'
and field =
'categories'
, respectively; count_fields()
returns the frequency
tables of the specified YAML fields, such as the counts of tags and
categories.