Add JupyterLite Demo

[bollwyvl]

Docs

References

• fixes #40

Tasks

• [x] add jupyterlite to docs environment, build

Future Work

• [ ] add a tour
• [ ] add a widget-based link builder notebook
  • [ ] JVC-PUBLIC
  • [ ] room that uses the public WebRTC signaling server provided by yjs
  • [ ] workspace, once supported
  • [ ] ???