Maybe add a section on command line help?

[jhodgdon-drp]

Issue description

It might be helpful to add a note on the Intro to the Command Line page that explains how to get help on commands.

For example, on Windows, most commands have a /? option that gives you help.
On Linux (and Mac?), most have a -h or --help option.

After giving an example (maybe on the delete commands?), it could also be added to the command summary at the end of the page.