Add UTF16 to cheat sheet
> Now that this is moving into the non Basic Multilingual Plane, it would be useful to also have the UTF-16 notation for these icons in the cheat sheet next to hex as that one can't be used directly in JSON or other text files. For example, `nf-md-folder` hex value is `f024b` which can't be used as `\uf024b` unlike before. From a user perspective that's not very accessible, so having the UTF-16 notation (`\udb80\ude4b`) in the sheet would be very useful.

_Originally posted by @JanDeDobbeleer in https://github.com/ryanoasis/nerd-fonts/issues/365#issuecomment-1398110379_
            