update ndjson links due to domain expiry/resale (#24306)

command/agent/event_endpoint.go

@@ -115,7 +115,7 @@ func (s *HTTPServer) EventStream(resp http.ResponseWriter, req *http.Request) (i
 			if _, err := io.Copy(output, bytes.NewReader(res.Event.Data)); err != nil {
 				return CodedError(500, err.Error())
 			}
-			// Each entry is its own new line according to ndjson.org
+			// Each entry is its own new line according to https://github.com/ndjson/ndjson-spec
 			// append new line to each entry
 			fmt.Fprint(output, "\n")
 		}