Reconsider Provenance file Keywords for being possibly too general

This reminds me that the list of keywords in the citation files (this one and .zenodo.json) is perhaps worth re-thinking. If these are the keywords that govern when this repo shows for a keyword being searched, several of the keywords seems too generic for expecting this repo to be an appropriate member in set of matches. For example, I'd say it's questionable whether this repo should show up when someone searches for "data", "demos", or "models.

Adding "demos" here doesn't really change the nature of the keywords (if they're too general, they already were so; if they were reasonably good, this should not change that), so may as well be part of the change set. But maybe worth discussing as a separate issue.

_Originally posted by @hlapp in https://github.com/Imageomics/catalog/pull/132#discussion_r3738823712_

Review the keyword lists in the citation files and .zenodo.json, starting with the entries discussed in the issue such as "data," "demos," and "models." Determine which terms are too general for repository discoverability and update the metadata consistently; the keyword lists should reflect the repository's specific content when done.

Written by the indexing model from the issue text.