Updated examples as requested from specification PR #970

[VisLab]

This PR is done in conjunction with a rewriting of the 03 HED.md appendix in the BIDS specification
which corresponds to PR: bids-standard/bids-specification#970.

The following changes were made:

1. The eeg_hed_small was renamed eeg_ds003654s_hed and updated to better correspond to the version of ds003654 on openNeuro.
2. Additional copies eeg_ds003654s_hed_inheritance and eeg_ds003654s_hed_longform were added. These datasets are modifications of eeg_ds003654s_hed designed to demonstrate different forms of tag organization for testing and illustration.

Review requested: @sappelhoff @dorahermes @Remi-Gau

[sappelhoff]

+1, it's good to have these examples (both for testing, and to point users to them). I think now the only thing we are missing is an HED example where an HED column in events.tsv is used, right? I know that feature is not really how HED should mainly be used ... but if it's a feature, it might as well be tested.

Thanks for editing the README, it's all very clear to me.

You need to remove the .idea/ folder that you accidentally (?) commited.

CI failures seem to be due to microscopy, which is not yet in "stable" validator

[VisLab]

Thanks for spotting the .idea. Yes, the failures are due to microscopy and not these changes.

We'll add an example of the HED column in a future PR. There are a couple of other test cases regarding definition expansion that will also need to be added in a future PR.

I'd like to get this PR through with the HED.md update PR, so that we can move forward on the library schema update.

[sappelhoff]

Merged- thanks @VisLab