(#1535) - clickable api chapters

!['clickanim'](http://i.imgur.com/jGqlb7J.gif)

Simple mini-partial that accepts two params:
title: the displayed text (required)
hash: the #link (optional, will be generated from title)

e.g.
```html
Input:
{% include anchor.html title="Pokemon Gotta Catch Em All" %}
Output:
<a href='#pokemon_gotta_catch_em_all'  name='pokemon_gotta_catch_em_all'>Pokemon Gotta Catch Em All</a>
```