[Modules] Simplified way to define module help message

[Xavier D. <xav...@gm...>]

Dear All,

Next version will introduce the `module-help` modulefile command to
provide a simpler way to define modulefile help message:

https://modules.readthedocs.io/en/latest/MIGRATING.html#simplified-way-to-define-module-help-message

Regards,
Xavier