Add targetHints to links.json

Author: handrews

links.json

@@ -26,6 +26,9 @@
             "description": "JSON Schema describing the link target",
             "allOf": [ { "$ref": "hyper-schema#" } ]
         },
+        "targetHints": {
+            "description": "JSON representation of likely metadata such as response headers, with a protocol-dependent format"
+        },
         "mediaType": {
             "description": "media type (as defined by RFC 2046) describing the link target",
             "type": "string"