[chore] proper docs testing with approvals and jbang

[andreaTP]

Now that we have more structured docs we need to move on with the testing infrastructure of the examples.

I believe this is easier to maintain and evolve than before, it also has much nicer error messages when something goes wrong.
Since I was at it, I removed the npm package-lock in favor of yarn.lock.

This PR remove the testing from the Readmes as we need to move that documentation to docs.