v0.8.0

Now

- item
  - nested
- item 2
{.green}

gives

<ul class="green">
<li>item
<ul>
<li>nested</li>
</ul>
</li>
<li>item 2</li>
</ul>

not

<ul>
<li>item
<ul class="green">
<li>nested</li>
</ul>
</li>
<li>item 2</li>
</ul>

Documented ambiguity in nested lists, see #32.