Write end-to-end examples

[remiadon]

Make examples fully BIDS compliant

• [x] bids folder structure
• [ ] include sidecar .json file

[remiadon]

we should also add a prov suffix to all sidecar files, as mentioned in the spec, as spotted here https://docs.google.com/document/d/1vw3VNDof5cecv2PkFp7Lw_pNUTUo8-m8V4SIdtGJVKs/edit?disco=AAAAMwpJ4B8