Add about the need to bidsignore dandiset.yaml

[yarikoptic]

No description provided.

[Copilot]

Pull Request Overview

This PR enhances the BIDS validation documentation by adding important guidance about excluding DANDI-specific files from BIDS validation and expanding validation tool recommendations.

Key changes:

• Adds instruction to use .bidsignore file for dandiset.yaml to prevent BIDS validation errors
• Expands validation recommendations to include both BIDS validator and dandi validate command
• Notes that dandi upload also performs validation

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[kabilar]

Suggested change

	- perform validation of the files ideally using both
	- the stock [BIDS validator](https://bids.neuroimaging.io/tools/validator.html)
	- and [dandi validate](https://dandi.readthedocs.io/en/latest/cmdline/validate.html) since it would also validate using other helper tools such as [NWB inspector](https://nwb.org/tools/core/nwbinspector/) if you have NWBs, to ensure that your data is compliant to all used standards.
	- perform validation of the files using [dandi validate](https://dandi.readthedocs.io/en/latest/cmdline/validate.html) to ensure your data is compliant with the BIDS and/or NWB standards. Alternatively, you could independently validate your files using the [BIDS Validator](https://bids.neuroimaging.io/tools/validator.html) and/or [NWB Inspector](https://nwb.org/tools/core/nwbinspector/).