Homepage: featured items clickable

[mark-dce]

On the default homage (#21), make the full feature tile clickable.

• [ ] when I click on the feature item title, I go to the feature item pid show page (image or collection)
• [ ] when I click on the feature item image, I go to the feature item pid show page (image or collection)
• [ ] when I click anywhere inside the tile's bounding box, I go to the feature item pid show page (image or collection)