Add support for regional indicators

[networkException]

The character making up flag emojis itself are also common to get rendered nowadays, a list of them can be found here https://en.wikipedia.org/wiki/Regional_indicator_symbol#Unicode_block

[JoshuaKGoldberg]

👋 new junior maintainer here, picking up old threads - @networkException (or anybody else), is this still of interest to you? If so, could you provide a code snippet showing node-emoji not behaving as expected?

Note that #113 switched to using emojilib internally for emojis.

Note also that #132 is in the works to bump to the latest version of emojilib.

[JoshuaKGoldberg]

Closing out as aged away. If anybody can provide a code snippet showing the difference in actual vs expected that'd be lovely, we can always reopen / make a new issue. Thanks!