More clear formatting for posts.

Right now it's: `feed_name - content - feed_item_link`. Place the name and link on a separate line. In markdown, I'd imagine it to look like this:
```
[feed_name](feed_link): [Post](feed_item_link)

content
```

Subject line / feed item title can be the same as the content, or too long, so I'd rather not use it instead of the static 'Post' text.