Respect Loose Lists

[wbw20]

As mentioned in the original spec

<p>Asterisks loose:</p>

<ul>
  <li><p>asterisk 1</p></li>
  <li><p>asterisk 2</p></li>
  <li><p>asterisk 3</p></li>
</ul>

should render as:

Asterisks loose:

*   asterisk 1

*   asterisk 2

*   asterisk 3

but instead renders as:

Asterisks loose:

* asterisk 1
* asterisk 2
* asterisk 3

These are called loose lists and many common markdown renderers support them. Might be something to consider adding support for.

[leeoniya]

done, try it out.