This is a proof of concept for an alternate, web-based UI. It is in the very
early stages, and does not do anything useful at the moment.

The code uses the helpers in ../tslib to communicate with the Python
backend defined in ../pylib/anki/pybackend.py, leveraging the same
protobuf definitions used for the Rust/Python bridge.

To try it:

- ensure 'tmux' is installed
- run 'make run' in the top level folder and close Anki
- copy a test .anki2 file to ~/test.anki2
- run 'make run' in this folder