Plugins are responsible for defining their own help messages, or None if the default is to be used.
help plugin lists as plugins with their description if one is provided now (used to be help plugins).
help plugin <plugin-name> displays the plugins help message if one exists (default message if none was provided). Otherwise displays message that a plugin with such a name doesn't exist.
Notes:
help pluginlists as plugins with their description if one is provided now (used to behelp plugins).help plugin <plugin-name>displays the plugins help message if one exists (default message if none was provided). Otherwise displays message that a plugin with such a name doesn't exist.