New: upload your group logo!

While we are working on the conflict resolution feature, there’s always time to tackle some smaller tasks :smiley: A new contributor asked for a task to get started with and adding a logo to groups seems to be such task. After a few days of back-and-forth, the first implementation is ready!

So, from today on, you can upload your group logo on the group edit page. It gets shown in the group gallery, on the group preview page and in the top bar when you are inside that group (replacing the Karrot logo).