Right, I think that there should be an editor that can open a project folder (consisting of json files and assets like images or sound clips) that teachers can

Right, I think that there should be an editor that can open a project folder (consisting of json files and assets like images or sound clips) that teachers can use and share with each other (because they understand copying a folder and naming it v2 then emailing it to a colleague), but that folder could also be uploaded as a repo to github for more organized projects. You could also have a cloud service to store the project files, and then the teachers can just login to the editor and click save to upload their latest copy of the course.