I went to view my repository on Github.com and was presented with a giant pink unicorn and a message saying:
No server is currently available to service your request.
Does this mean something is wrong with my repository or account? Have I made in error in my repository?
If not, what's the issue?
It means GitHub is down. It means you can't use GitHub any more. See https://status.github.com/.
I guess you can bask in the unicorn's glory or something? Other than that, you can do pretty much whatever you like.
One thing that also isn't down is https://developer.github.com/.