--open in conjunction with --output

[jasonkarns]

It's nice that discify has a built in server, but it's rather confusing that --open doesn't work when used in conjunction with --output.

Why not just open the static file that is written immediately upon writing? Or at the very least, make it clear in the documentation/help that --open and --output are mutually exclusive. (I kept repeatedly trying various configurations wondering why --open wasn't doing anything, before I finally tried removing --output.)