graphql-js.org is only partially deprecated

[yaacovCR]

It looks like graphql-js.org has been deprecated in favor of graphql.org/graphql-js. Our README even points to graphql.org/graphql-js.

So we really should:

1. add the latest additional content from graphql-js.org to graphql.org/graphql-js (see add additional content from graphql-js repository graphql.github.io#1782)
2. redirect from graphql-js.org to graphql.org/graphql-js or point graphql-js.org to graphql.org/graphql-js
3. remove the old website from the graphql-js repo.

I am not in a position to do 2, but have submitted a PR doing 1, and once 2 is done, I can do 3.

[yaacovCR]

@saihaj @dimaMachina