Essell

- [x ] The issue is present in the latest release. - [ x] I have searched the [issues](https://github.com/brocaar/chirpstack-gateway-bridge) of this repository and believe that this is not a duplicate....

enhancement to show format in output

1

This pull request simple adds the '-show_format' parameter to the command line so that useful information, such as tags metadata, can be seen in the json output.