Why do you need to use the word compile?
If you briefly scroll through the thread, you'll notice people are posting their sprites on the thread itself for free use and for the person who organised the thread (I presume), to upload them to GitHub. It's not publicly changeable, therefore, you have no need to worry about compiling anything. Just create sprites, upload them to your image host, then post them into the thread. Or even better, add them as an attachment.
Like you, other people have their own ways of working. If you have a preference, that's your preference. The only reason for you to access GitHub is an alternative source to download the existing files. The person who organised it was encouraged to upload to GitHub by the community, which, once again, has no impact on the way you can share sprites.
Anyway, back to topic. I have to say, the 64x64 looks amazing!