Add synopsis of tool to help output

[pcgeek86]

The underscore-cli project is pretty impressive. I think it would be useful for the help output to provide a synopsis of the tool's purpose, however. It would be nice if this were a trend for all command line tools, similar to how PowerShell has a structured, built-in help system.

underscore-cli is a command line tool, built on nodejs, that enables you to ....

The current help output doesn't have any synopsis (screenshot below).

Cheers, Trevor Sullivan Microsoft MVP: PowerShell