Consider using Intl api

I really like the way Luxon does localization and time zone support by using Intl.DateTimeFormat

For time zones, it allows the user to specify any time zone without any extra files to download compared to solutions for other libraries that are quite large. See their timezone docs and code for more details. This could be a possible method of implementing https://github.com/iamkun/dayjs/issues/323, https://github.com/iamkun/dayjs/issues/249, https://github.com/iamkun/dayjs/issues/46

For localization, it's far easier to maintain because you do not need to create or maintain any translations on your side. This could fix several issues such as https://github.com/iamkun/dayjs/issues/416, https://github.com/iamkun/dayjs/issues/415, and https://github.com/iamkun/dayjs/issues/171. It's also easier for users because they don't need any extra files and everything works out-of-the-box. See their Intl docs and code for more details

Would there be any interest in this approach?