Add hackernews graphql api tutorial to other resources

[Glyphack]

Hi, I wrote this tutorial a while back, and it still has some visitors. Add it here if you think it would be helpful for newcomers.

Just a note is that the gqlgen version is not the latest here, but I do update the tutorial from time to time.

I have:

• Added tests covering the bug / feature (see testing)
• Updated any relevant documentation (see docs)

[StevenACoffman]

Yay! thanks for writing this and for bringing it to our attention.

[coveralls]

Coverage remained the same at 75.097% when pulling 4d81cd0 on Glyphack:master into c2526ba on 99designs:master.