[star] doesn't always show the star icon

[jordanweiler]

The [star] text gets replaced with the special icon (<span class="icon-special" title="Star">) within replaceSymbols so it works on most cards but not when hovering over a card for the preview. That logic in app.format.js replaces [star] with <span title="star" class="icon-star" /> which doesn't render because that's not the correct class name.

We either need to rename the icon-special class to icon-star and then [star] should work or we should start using [special] instead of [star] in card text to represent the star icon.