README.md

[WaDelma]

This repo should include some kind of readme that tells potential contributors how to add new test exercises and what the exercises should contain.

[jamo]

Probably, thou this is mainly to provide simple exercises for demos and such, so we expect only people who create new language supports to contribute here. Well it's not super obvious what we hope to have here. So I'll add a readme soon (unless someone else has time before I do)