Request Feat: Collections

I would like to use this as a portfolio grid.

I would like to group images, and the parent grid would use a preview image as the cover and when you click on it, it will show all of the images underneath that folder aka collection.

Also would like the option of "caption text" so I can put the collection names on hover. Perhaps the possibility to have a sidebar consisting of content (raw ng components/html), although I could do this modification myself with the help of material.

Thanks for starting this project!