You don't need to worry about the contents of this directory - just use emoji.php,
emoji.css and emoji.png in the parent directory.
The scripts in this directory allow you to build the library from the emoji-data source material.
The emoji-data repo contains a list of emoji with supporting images (and spritesheets).
We use this data to build the PHP map and the CSS file:
./build.sh
The following files are created by this process:
../emoji.png
../emoji.php
../emoji.css
../table.htm