Writing area

https://trello.com/c/NElTBCxh/54-as-a-user-i-want-a-nice-place-to-write-things

![selection_034](https://cloud.githubusercontent.com/assets/8248100/5289749/cf72cf74-7b0e-11e4-91dd-73e344803606.png)

``` html
<div class="metrics">
  <span class="word-count">0</span>
  <span class="words hidden">words</span>
</div>
```