configure_meta_tags() in conf.py prepares a block of HTML to just include in the HTML transformation of the docutils doctree. I'd someday like to extend docutils to generate RDFa with those headings and attrs as labels and properties
https://github.com/wrdrd/docs/blob/master/docs/conf.py#L305
https://twitter.com/westurner/status/1189601375505862657 :