Suggestion: generate simple html for displaying feed contents

[vivlim]

I think there are two places it'd be useful to render feed content:

1. In the editor so you can see all the previous posts that are in the feed, when adding another
2. Being able to deploy a sidecar index.html that reads the feed and renders it. I think that rendering should happen in the browser, otherwise users will need to update index.html and the feed every time they make a post. I really like the simplicity of a single file containing all the textual content.

(perhaps these could be two separate issues as well)