feat(generators): add cli-output

[atinux]

Add cli-usage generator, inspired by https://github.com/h3js/srvx/blob/main/automd.config.ts

[atinux]

I guess we will need to first publish a new version of automd to support the cli-usage in order to update undocs to finally be able to generate the docs with the latest version of automd 😄

[pi0]

Im thinking we could make a generic cli-output generator and a shortcut cli-usage that automatically generates —-help. (or an option for cli-output to do this)

[atinux]

Updated to cli-output with:

<!-- automd:cli-output command="automd" args="--help" -->
<!-- /automd -->

and shortcut:

<!-- automd:cli-output command="automd" usage -->
<!-- /automd -->