context.json

{
	"@context": {
		"@vocab": "http://www.w3.org/ns/dcat#",
		"dp": "http://dataportals.net/ns/dp#",
		"schema": "http://schema.org/",
		"rdfs": "http://www.w3.org/2000/01/rdf-schema#",
		"xsd": "http://www.w3.org/2001/XMLSchema#",

		"url": "@id",
		"linked_portals": {
			"@id": "dp:linkedPortal",
			"@type": "@id"
		},
		"version": {
			"@id": "schema:version",
			"rdfs:comment": "Version of the DataPortal schema being used"
		},
		"number_of_datasets": {
			"@id": "dp:numberOfDatasets",
			"@type": "xsd:integer"
		},
		"datapackages": {
			"@id": "dp:dataPackage",
			"@type": "@id"
		},
		"links": {
			"@id": "dp:link",
			"@type": "@id"
		},
		"themes" : {
			"@id" : "dp:theme"
		}
	}
}

dataportal.json

{
"@context" : "context.json",
"language": "en",
"name": "Paris Data",
"description": "City of Paris Open Data portal",
"url": "http://opendata.paris.fr/",
"linked_portals": ["http://data.gouv.fr", "http://data.iledefrance.fr"],
"data_language": ["fr"],
"modified": "2016-03-04T13:44:44+00:00",
"themes": ["Culture, Heritage", "Education, Training, Research, Teaching", "Environment", "Transport, Movements", "Spatial Planning, Town Planning, Buildings, Equipment, Housing", "Health", "Economy, Business, SME, Economic development, Employment", "Services, Social", "Administration, Government, Public finances, Citizenship", "Justice, Safety, Police, Crime", "Sports, Leisure", "Accommodation, Hospitality Industry"],
"links": [
  {"url": "http://opendata.paris.fr/explore/download/", "rel": "Catalog CSV"},
  {"url": "http://opendata.paris.fr/api/", "rel": "API v1"},
  {"url": "http://opendata.paris.fr/api/datasets/1.0/search?format=rdf", "rel": "Catalog RDF"}
],
"version": "1.0",
"number_of_datasets": 176,
"organization_in_charge_of_the_portal":{
  "name": "City of Paris",
  "url": "http://www.paris.fr/"
},
"spatial": {
  "country": "FR",
  "coordinates": [
    48.8567,
    2.3508
  ],
  "locality": "Paris",
  "data_spatial_coverage": "a Geojson with the data coverage"
},
"type": "Local Government Open Data Portal",
"datapackages": [
  "http://opendata.paris.fr/explore/dataset/liste_des_sites_des_hotspots_paris_wifi/datapackage.json",
  "http://opendata.paris.fr/explore/dataset/points-de-vote-du-budget-participatif/datapackage.json",
  "http://opendata.paris.fr/explore/dataset/cinemas-a-paris/datapackage.json"
  ]
}

Working on turning it to JSON-LD....