Added a simple and complex metadata example to proposal 1, plus an extension using schema.org.
Added a note about JSON-LD with link back to Gist containing metadata, JSON-LD context and RDF triples experiments.
Added reference to external @context and a @type.
Fixed invalid JSON.
Added a simple and complex metadata example to proposal 1, plus an extension using schema.org. Added a note about JSON-LD with link back to Gist containing metadata, JSON-LD context and RDF triples experiments. Added reference to external @context and a @type. Fixed invalid JSON.