-h, --help                   output usage information
-V, --version                output the version number
-P, --parser <parser>        use markdown parser, remark | marked | showdown
-p, --port <port>            server port (defaults to 3333)
-b, --browser <browser>      browser name to open
-c, --css <name>             use customize css file for styling
-w, --width <width>          limit the width of the document (defaults to 800px)
-i, --highlight <highlight>  set highlight style
-t, --timeout <seconds>      exit preview if idle (defaults to 3s)
-o, --output <filename>      write to file