Cover images for your assignments

We have updated the assignments page to add some cover images for all your assignments.

When creating or updating an assignment, you can now optionally upload a picture to use as cover or choose a beautiful photo from Unsplash. We also added some nice default covers for the assignments that don't have a cover.

When viewing the assignments list, you now have the number of unread comments from students as well shortcuts to their work when clicking on the different labels ("Turned in", "Started", etc.).