Print a message in the color that tells how something is to be used.

    Use this command to tell the user how something works, either because
    they got it wrong, or because they're curious, such as with a "help"
    command.

Examples:

    usage "Need a string parameter."
    usage "$sBigString" # Put big strings in quotes so it's one parameter.

Usage: usage <action:help> # Where action is:

    help  Help by showing these instructions.
    *     Print a message in the color that tells how something is to be used.  [default]