Make sure that the demo instruction from the README works with the new demo

# Why?

It's important that the users can enjoy an instructive demonstration and learn from it.

# What?

- [ ] Run steps in the README
- [ ] Make sure that the numeric outputs are produced at every run (lean run of Main.lean via `lake exe wasm` or `./build/bin/wasm`) and lurk run via `yatima`.
- [ ] Make sure that said numeric outputs are the same.

Follow the demo steps in the README and run Main.lean through `lake exe wasm` or `./build/bin/wasm`, then run the corresponding example with `yatima`. Compare the numeric outputs from both runs and confirm that every run produces matching results.

Written by the indexing model from the issue text.