The html structure. The only real important thing here is the 'data-key' attribute. It has to be a [valid JSON](http://jsonlint.com/) array of strings.
```html
<divid="grid">
<divclass="item"data-key='["photography"]'>
@ -49,6 +51,7 @@ The html structure. The only real important thing here is the 'data-key' attribu