New workspace with a full graphical Linux desktop

Thanks to Nicolas Nytko (CS MS '22), PrairieLearn has a new desktop workspace image. This is a full Linux desktop that will allow students to run whatever graphical or terminal applications are included in the workspace image. Like existing workspaces, this desktop environment is accessed within the student's web browser, is fully persistent, and is coupled with the external autograder system.

This new image is provided as prairielearn/workspace-desktop and comes with a small set of pre-installed applications. Installing extra software can be easily done by creating your own Docker image that uses this one as a base.

To try out the new workspace image, you can demo the demo/workspace/desktop question in the example course XC 101 or add these options to one of your existing questions:

"workspaceOptions": {
    "image": "prairielearn/workspace-desktop",
    "port": 8080,
    "home": "/home/prairielearner"
}