Add list ability to markdown rendering

[mononoken]

Lists should be able to be implemented using syntax like:

- item 1
- item 2
- item 3

[mononoken]

The lists were already being rendered by redcarpet gem. However, the markers were not appearing because the prose-invert color matched the background color.

[mononoken]

ce35ef5ebab331dbe0cce8260880e94d01685893 fixes by adding marker color styling to the notes.