allow newline after Usage / Options

[tj]

it just outputs the help, no error or anything, kinda confusing, having them squished looks weird but that whitespace should be optional and left up to the author anyway. Same with leading/trailing whitespace, I'm not a fan of stdio that is shoved against the terminal edges so a tool forcing me to do that is a little meh

[keleshev]

/cc @kbatten, @mboersma

[aviddiviner]

I have a fork which should handle this, you can just set your own HelpHandler func and choose what to do. Take a look at the docs if you're interested. https://github.com/aviddiviner/docopt-go#api

[mboersma]

Now that the above fork is merged back upstream, this should be easy as described above.