use "@type" instead of rdf:type

[ethieblin]

This is necessary for JSON-LD framing of the TD.
The security triples are not framed back correctly with "rdf:type" instead of "@type" in the context.
The input data in these examples is a set of security RDF triples which have been transformed into JSON-LD with rdflib (python library for rdf).
The same output is obtained after uploading and retrieving the triples from a SPARQL endpoint.

<urn:uuid:55f01138-5c96-4b3d-a5d0-81319a2db677> a td:Thing .
<urn:uuid:55f01138-5c96-4b3d-a5d0-81319a2db677> td:definesSecurityScheme _:b0 .
<urn:uuid:55f01138-5c96-4b3d-a5d0-81319a2db677> td:hasSecurityConfiguration> <https://json-ld.org/playground/nosec_sc> .
_:b0 a wotsec:NoSecurityScheme .
_:b0 td:hasInstanceConfiguration <https://json-ld.org/playground/nosec_sc> .

Framing with the original context gives playground with original context

"securityDefinitions": {
    "nosec_sc": {
      "@type": "nosec"
    }
  }

Framing with the new context gives playground with this MR context

"securityDefinitions": {
    "nosec_sc": {
      "scheme": "nosec"
    }
  }

[ethieblin]

@wiresio fyi

[sebastiankb]

from today's TD call:

• it seems that the render script needs to be updated to have the change permanent
• the td-context-1.1.jsonld is generated by the render script and should not change manually
• @ethieblin can you update the script as well?

[ethieblin]

@sebastiankb I manually changed context/wot-security-context.jsonld then ran the script merge.js to get the td-context-1.1.jsonld changes.
I will check that the other scripts of render.sh are fine with this change.

[ethieblin]

I updated the toRDF.js file so that the ttl file do not change (but in the other PR, I can move the commit or merge the two PR into one if you prefer): 5824fe3

[w3cbot]

ashimura marked as non substantive for IPR from ash-nazg.

[sebastiankb]

from today's TD call, decided to merge