WIP: Add authors to project metadata

[jo-mueller]

Fixes ome/ngff#315

Authors and Contributors to the ngff specification should be acknowledged for their contributions, as pointed out in ome/ngff#315. At the 2025 NGFF Hackathon in Zürich, it was suggested to use the following list as a criterion for inclusion as an author:

• Contributed to repo (see repo insights)
• Wrote an RFC
• Wrote an RFC comment
• Wrote an RFC review

So far I added the authors in alphabetical order.

Copilot description

This pull request updates the author and affiliation metadata for the Next-generation file format specification to provide a complete and detailed list of individual contributors and their institutional affiliations. The changes enhance attribution and traceability for the project, replacing the previous generic community author with a comprehensive, structured list.

Author and Affiliation Metadata Updates:

• Replaced the single "NGFF-community" author entry with a detailed list of individual authors, including full names, affiliations, and, where available, ORCID IDs in ngff_spec/CITATION.cff.
• Expanded the ngff_spec/myst.yml file to enumerate all contributors by name, with additional metadata such as GitHub usernames, ORCID IDs, and structured affiliations. Also introduced a new affiliations section mapping short IDs to full institutional names and ROR identifiers.

[github-actions]

Automated Review URLs

• Readthedocs