Port from colab to deepnote #144

Making this issue to track my progress

• Verify drake can work from docker
• Upgrade docker to focal
• Check ipywidgets. Update: it is working now in beta (requires deepnote to flip a per-user bit). Will be out of beta soon (but perhaps not in time for the start of the term)
• Meshcat
  • Verify meshcat can work (via ngrok)
  • Meshcat launched via pydrake's meshcat doesn't show objects yet.
  • Try meshcat as-a jupyter cell. Update: Won't fix. Only allows https, so needs websockets not (free) ngrok.
  • Try meshcat w/o zmq (websocket only). Update: haven't found javascript kernel comms handler.
  • Rewrite Meshcat in C++ to pull out the zmq server, and address Meshcat in C++ RobotLocomotion/drake#13038 at the same time. See also move slider guis to meshcat #145.
  • Convert intro.ipynb (gui sliders, etc). Update: working well on my dev branch.
  • Reimplement ngrok or alternative. Consider ngrok alternatives #146
• Test x display rendering (via pyvirtualdisplay / xvfb) in clutter.ipynb. Update: @danzvara says he believes people have done this, but it is worth confirming.
• Evaluate interactive matplotlib (does it make sense w/o ipywidgets? do I need it?). Update @danzvara says it's not supported yet.
• Get torch/GPU workflow w/ manipulation dockerfile. Deepnote containers load nvidia drivers; I should, too. Update: likely won't fix for now; GPU machines are not free.
• Plan for sharing
  • I own Deepnote project; share entire project as read-only. Users duplicate the project, then copy files from /root/manipulation to ~/work as necessary to scribble.
  • Each chapter (even each problem?) can be a different project, so that the link to the project is the link to the notebook.
• Slowly convert each chapter / notebook.
• Update pset PR documentation.