Update README.adoc

README.adoc

@@ -55,6 +55,7 @@ Challenge: Express the link:https://docs.evolveum.com/midpoint/midprivacy/phases
 
 https://evolveum.com/a-road-to-axiom/ <= A Road to Axiom, a blog post by Radovan Semancik +
 https://dzone.com/articles/json-ld-building-meaningful-data-apis-via-codeship <= Why JSON-LD, An Introduction +
+https://json-ld.org/primer/latest/ <= JSON-LD Primer A Context-based JSON Serialization for Linked Data +
 https://github.com/digitalbazaar/jsonld.js/ <= JSON-LD Library; Any JSON tool will recognize JSON-LD as valid +
 https://github.com/digitalbazaar/jsonld-cli <= CLI version of the JSON API +