- was making this change for <wix-image> on Wix websites, but discovered after that this has already been done in e4593ff76d
- have tested document.createElement('wix-image') and document.createElement('foo_bar'), but can't find a canonical source for what is allowed in tag names.
- this restriction was originally introduced in #150 to prevent document.createElement('alt=""') i.e. a very malformed tag name