`yard -h` and `yard help doc` yield same output and do not mention other subcommands

[keithrbennett]

I was trying to learn more about using the server subcommand, so I tried yard -h, but there was no mention that it even exists.

On further investigation, I found that yard help lists the server subcommand, and yard help server gave me the information I wanted. Also, I compared the output of yard help doc with yard -h and found they were identical.

I suggest that the output of yard -h be modified to explain how to get information about the subcommands other than doc.

> yard -v
yard 0.8.7.4