Custom CSS doesn't apply to rendered HTML, only rendered Markdown

[t0dd]

I want to see two things:

1. HTML notes wrapped in an unstyled <div id="rendered-html" /> You know. In the same place in the view as the <div id="rendered-md" /> for markdown notes.
2. the equivalent of userstyles.css but for HTML. Because, of course, some of us want to style that rendering a bit differently than the default.