Feature/style menu slide

We need to keep the ``<script type="text/javascript" src="{{ "js/base.js"|static_url }}"></script>`` tag in here because it has important AJAX glue. You can just move

```javascript
$('.nav-menubutton').on('click', function (a) {
    $('body').toggleClass('menu-active');
});
```

out of the html template and into ``base.js`` and we should be all good.