- Added a fix for srcset in img tag. Thanks to Gauav Kumar for this contribution!
- Add test and documentation about adding custom self-closing tags.
- Although attributes are already escaped, we still have to output them
using quotation marks that are compatible with the escaped values, e.g.
if the escaped values contain unescaped double-quotes, then we must
single-quote the attribute, and vice versa. Note that it is not the task
of
absolutionto verify that the escapes are valid overall, only to do no harm when transforming the document's URLs.