Per the linked site (http://mths.be/details) and https://caniuse.com/#feat=details the <details> element is supported since Chrome 12/Safari 6/Firefox 49/Edge 79. IE 11 doesn't handle them, but we dropped the support for that browser.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
Michael Brown
Jarek Radosz
Kane York
Bianca Nenciu
Sam Saffron
Jeff Wong
Régis Hanol
Robin Ward