Rename extends which bring back standard list styles

# Rename extends which bring back standard list styles

Status: **Opened for visibility**
Reviewers: @jeffkamo @ry5n 

## Changes
1. Renamed the list extends to be a little bit clearer about what they're doing

## Notes
- I don't think this is necessarily the best way to handle these. We probably want to move these into utility classes once we have http://github.com/mobify/stencil going but for our first release this should work.