text: Title: Enhancement: Add new apps via uploading jupyter notebooks via drag and drop in the browser
  Body: It would be nice, if users could create new apps via uploading their custom jupyter notebooks via drag and drop in the browser on the home screen of mercury.
  
  Due to security concerns, this feature should only be enabled in trustworthy environments, e.g. via explicitly submitting an additional command-line argument `mercury run --enable-app-upload`.
  
  I am curious about your thoughts.