HERD name change

[mavaylon1]

Summary of changes

Updates ExternalResources to have a uniform name throughout the codebase and the literature, which is now "HERD".

PR checklist for schema changes

• [x] Update the version string in docs/source/conf.py and common/namespace.yaml to the next version with the suffix "-alpha"
• [x] Add a new section in the release notes for the new version with the date "Upcoming"
• [x] Add release notes for the PR to docs/source/hdmf_common_release_notes.rst and/or docs/source/hdmf_experimental_release_notes.rst

[mavaylon1]

Note: Merge after TermSet updates are merged

[rly]

Can you spell out what HERD stands for in the docstrings and release notes?

[mavaylon1]

Can you spell out what HERD stands for in the docstrings and release notes?

Good call. I added it here and also to the class in HDMF

[rly]

Thanks. Looks good to me!