Include yepnope to load polyfills

The plan would be to write examples in Handlebars partials, include them in code blocks and include them inside script tags like this:
```html
<script>
IntlDocs.ready(function () {
 {{>partial}}
});
</script>
```
It isn't going to be enough to just load the lib. We also need the data, and that depends on information the server has which we'll need to serialize to the client so that this can access it from a known `window` namespace.