We are planning to remove the controlled vocabularies from the CSV
files so we should not expect that this column will exist. Instead,
check if there is a controlled vocabulary in the data directory.
The controlled vocabularies were already exported once using the
util/export-controlled-vocabularies.py script so we don't actually
need them in the CSVs anymore.
Read vocabularies from the data/controlled-vocabularies directory
instead of exporting them from the schema itself. Also, I use the
name vocabulary.txt for all of them on the site since they are in
each field's directory already.
This script doesn't generate the docs itself. It actually only does
the schema parsing to generate the metadata term content and vocabs.
The docs site is generated by Hugo after running this.