zhiyelee/mdserver — pull request #3 by zhiyelee (2014-10-22 05:32:25+00:00)
Title: add help info

Add help info with commander.js
```sh
✍ mdserver -h

Usage: mdserver [options]

Options:

-h, --help output usage information
-V, --version output the version number
-p, --port serve with given port
-r, --root serve given path

```

resolve #2