Documentation - clarify where `link: true` goes

The JSS docs on observables mentions that one needs to use link: true, but does not mention where.

For example, given:

    this.styles = jss.createStyleSheet(this.css).attach()

It’s not clear which of the following is correct:

    this.styles = jss.createStyleSheet(this.css, {link: true}).attach()
    this.styles = jss.createStyleSheet(this.css).attach({link: true})

Seems like it’s neither; rather, if you trace .attach, it looks like it uses this.options.link, but the expected jss.options is undefined.

All to say, there’s a gap that needs to be filled about where link: true goes.

[kof]

yeah, I guess docs will never be perfect, thats one every one needs to send fixes like this one 😃

[HenriBeck]

Here it says that observables need the Sheet option link: true.

Also the options for a Sheet a declared here: https://github.com/cssinjs/jss/blob/master/docs/js-api.md#create-style-sheet

But I think we could add an example with how to use observables.