Single line-break not working in Markdown Preview

If you have a note with more than 1 list inside, the first list won't get the line-breaks.

For instance:

Replicated in: #1346793-zen

Start by reproducing the issue in Markdown Preview with a note containing more than one list, using the example and replicated note reference in this issue. Trace the Markdown Preview rendering path and compare the first list with later lists; done means single line breaks render correctly in every list.

Written by the indexing model from the issue text.