kafka-metadata-quorum.sh add-controller subcommand can't recognize argument --config

In KIP-853, it uses following command as adding controller example.

kafka-metadata-quorum --bootstrap-server <endpoints> add-controller --config controller.properties

However, it returns "kafka-metadata-quorum: error: unrecognized arguments: 'config'". In MetadataQuorumCommand, the "command-config" description is "Property file containing configs to be passed to Admin Client.". It's not controller property file. We should either update description of the "command-config", or update the MetadataQuorumCommand to align with KIP.