front-page images boost.org

There was discussion in Slack about "photos of the posters". Here are some ideas. If images are displayed on the front-page of boost.org, they might be

- a slideshow (interesting feature, a clickable slideshow).
- or, just static images

In either case, it would convenient to be able to update and change these images from time to time. Rotate the images. Even if they are static images. That leads to having a method in the control panel where photos can be uploaded and selected. Similar to "News". It might be based on the "News" functionality, or new.

the images should be stored in the S3 media bucket, in a folder /front-page-images , or /content-images, etc. The advantage of this compare to the git repo, is that the file size is not an issue. There is no need to consume many MB's of space in the repository, and then those images will be updated or replaced, but they cannot really be "removed" from git. An S3 bucket does not have a size constraint, and can store any number of photos.