Ahh, you about this. It is just a bunch of sprites. There is not font file thought it can be generated but now color font's aren't have much support in the apps... In godot for example you can use .fnt file which will emulate font...

But in general the font is just an image so you need to cut it and the letters in the order you need.... It is tedious process... I love idea of fnt file it is very natural