The documentation site seems to be down.

For me it also works. Please check your internet connection.
The github.io hosting server is working, the DNS is working too, I can't do nothing more about it - looks like some internet providers has some problems. You have to wait or find another website hosted by github.io that is not working and report the issue to them.
Funny enough it works on my mobile data but not on my WiFi. I guess its the google dns?
@MichalLytek Worked after changing my dns provider to open dns.
I'm getting the same IP from Google and Open dns.
Name: typegraphql.ml
Address: 195.20.50.182
typegraphql.ml is not working and IP itself leads to http://www.dot.tk/en/index.html?lang=en
P.s. just a few days ago it was okay.
@wanjas typegraphlq.ml is now typegraphql.com. Hope that helps