Command line option not properly documented

[LasneF]

given openapi-changes running the command line without argument gives the following message

Available Commands: completion Generate the autocompletion script for the specified shell console Interact with OpenAPI changes in an interactive terminal UI help Help about any command html-report Generate the sexiest, most interactive diffing experience you have ever seen. report Generate a machine readable report for what has changed summary See a summary of changes

but looks there is no documentation about the completion one (that looks not clear ... 🤨)