Define GraphQL SDL directives for RDF concepts

[saerdnaer]

I think one of the first steps of this group should be defining a recommendation / standard on how to map GraphQL types/attributes to a RDF entity, e.g.

type Item @sameAs(uri: "https://schema.org/PodcastEpisode") {
  id: ID!
  title: String @sameAs(uri: "https://schema.org/name")
  …
} 

To be able to inspect this addional annotations from external endpoints https://github.com/graphql/graphql-wg/blob/main/rfcs/AnnotationStructs.md aka graphql/graphql-spec#300 is required to speced and implemented