fix(juniper_netscreen): update README.md

Author: pkoutsovasilis

packages/juniper_netscreen/docs/README.md

@@ -164,6 +164,8 @@ An example event for `log` looks as following:
 | http.request.method | HTTP request method. The value should retain its casing from the original event. For example, `GET`, `get`, and `GeT` are all considered valid values for this field. | keyword |
 | http.request.referrer | Referrer for this HTTP request. | keyword |
 | input.type | Type of Filebeat input. | keyword |
+| log.file.device_id | Device Id of the log file this event came from. | keyword |
+| log.file.inode | Inode of the log file this event came from. | keyword |
 | log.file.path | Full path to the log file this event came from. | keyword |
 | log.flags | Flags for the log file. | keyword |
 | log.level | Original log level of the log event. If the source of the event provides a log level or textual severity, this is the one that goes in `log.level`. If your source doesn't specify one, you may put your event transport's severity here (e.g. Syslog severity). Some examples are `warn`, `err`, `i`, `informational`. | keyword |