Ellipsis not documented

When greping through the repository I couldn't find a single occurrence of the word 'ellipsis'.

On the GoDoc page I found one example where Bind() is used to bind to a struct containing Host []string.

I didn't find any good way to get ellipsis options without binding to a struct. In examples/fake-git/fakegit.go I found this line cmdArgs := args["<args>"].([]string), but any casting error can't be caught here. Is there a better way?

In my opinion all this should be documented. If you can tell me about any functionality I missed, I'd be happy to write a paragraph for the GoDoc documentation and create a pull request.