Add option to use " or ' for attribute quotes

https://html-validate.org/rules/attr-quotes.html lets us use either " or ' quotes (or no quote or auto). I would like to use a rule where the quotes need to be there, but they need to be either " or '. The current options seem to allow only either of the two or disable checks. I would like to check that a quote is used, but use leniency on the type of quote (due to the used templating system that might have " around the occurrence of the attribute itself.