Document how to use secondary actions in lists

Bug, feature request, or proposal:

Improved documentation

What is the expected behavior?

It should be possible to include one or more buttons (or "infos") as a secondary action in a list item per the spec.

What is the current behavior?

The List documentation and examples do not show secondary actions.

Is there anything else we should know?

The documentation for Lists in Material 1 show extensive examples, including (at the very end) the use of multiple secondary actions, via the md-secondary class. I'm guessing this is probably already possible in Material 2 but I can't figure out how. (For the time being, I'm hacking it together with manual float:right and some margin twiddling.)