• fix: when importing 'temporal-polyfill' or 'temporal-polyfill/impl',
  the symbol DateTimeFormat is exported when in fact Intl should be exported
  according to the temporal-spec package. (#28)
  Potentially BREAKING CHANGE for vanilla JS users importing DateTimeFormat.
• fix: closed off potential attack vector for ReDoS attacks on regular
  expressions that parse ISO datetime strings (76a6aca)