This will generate a cheatsheet file for Twemoji Awesome. To generate,
make sure the twemoji-awesome submodule and the twemoji-possum
sub-sub-module is up-to-date, then run npm run build in the root directory.
The output files in the docs directory will produce a website list of
twemoji and their class names.
The cheatsheet can be viewed at https://kamalasaurus.github.io/twemoji-awesome-cheatsheet/