Update documentation

[vinferrer]

Summary

In the last hackathon there has been many enhacements that render part of the documentation outdated.

We need to

Next Steps

• [ ] add documentation about split multi-run physiological recordings
• [ ] Update Bidsdify data documentation now that we have the participants.tsv, description_file.json
• [ ] Update documentation now that most of the files go to code/coverage folder
• [ ] Generated report documentation once #243 is finished
• [ ] Now every multi-frequency output has a resample time channel and a resample trigger channel as soon as #288 is finished
• [ ] Pretty sure I am missing something else

[sangfrois]

Thanks for the initiative @vinferrer !

Should we add testing for multirun as well in that PR or should it be another one?

[vinferrer]

Actually each of those points could be a PR. The testing is independing from all this

[RayStick]

Mention somewhere in the documentation that:

• TRs within a scan are assumed to have even spacing.
• All TRs are considered at the moment (none can be ignored)