Update README.md

Author: nilportugues

README.md

@@ -285,6 +285,14 @@ Content-type: application/vnd.api+json
                 },
                 "comment": "Have no fear, sers, your king is safe."
             },
+            "relationships": {
+                "user": {
+                    "data": {
+                        "type": "user",
+                        "id": "2"
+                    }
+                }
+            },
             "links": {
                 "self": {
                     "href": "http://example.com/comments/1000"