Original request:
I couldn't find the robots.txt, but anyway I don't know if this is local to my machine, but archiving the github.io website on the wayback machine returns an error.
https://web.archive.org/save/https://github.com/visualizingthefuture/examples-repository
The github.com urls work fine.
archive.is is working fine, which is what leads me to believe it is the robots file.