Feat: add `rel="http://www.w3.org/ns/json-ld#type"` link relation.

[ioggstream]

When

• I interpret JSON as JSON-LD using https://www.w3.org/TR/json-ld11/#interpreting-json-as-json-ld
  and rel="http://www.w3.org/ns/json-ld#context"

I Expect

• A way to associate a @type (e.g., using something like rel="http://www.w3.org/ns/json-ld#type" ).

Instead

• Only rel="http://www.w3.org/ns/json-ld#context" is supported.

cc: @stefanone91 @mfortini