docs: Fix CONTRIBUTING.md to create project

[thomass-dev]

Closes #1026 .

[sylvaincom]

Thanks, I did not review the code but tried it out and it works. But in the quick start, do we actually want someone to do all of that?

make install-skore
skore create
make build-skore-ui
make serve-skore-ui

[augustebaum]

Thanks, I did not review the code but tried it out and it works. But in the quick start, do we actually want someone to do all of that?

make install-skore
skore create
make build-skore-ui
make serve-skore-ui

All of these steps do meaningful things; for now this seems like the simplest workflow