Add additional information to project CITATION.cff file

[mhucka]

Changes:

• Add orienting comments to the top of CITATION.cff, edit field text a little bit, and add more identifiers and keywords

• Add a GitHub Actions workflow that will update the version number and date in CITATION.cff upon new releases in GitHub

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.13%. Comparing base (a9c9009) to head (95ebdce).
Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7140      +/-   ##
==========================================
- Coverage   98.13%   98.13%   -0.01%     
==========================================
  Files        1093     1093              
  Lines       95579    95579              
==========================================
- Hits        93797    93796       -1     
- Misses       1782     1783       +1     

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[pavoljuhas]

Please remove the on-release workflow. The overhead with maintaining, updating and debugging the workflow is likely going to take more effort than updating the citation manually. The version and date in the citation are not that critical to justify extra work.

To ensure citation file stays up to date, please add a short note to https://github.com/quantumlib/Cirq/blob/main/release.md#bump-the-main-version. I'd be fine leaving it at that, but if you prefer some automation, we can add a simple job to ci-daily.yml, which would cross check citation version / date with those of the last release tag. This can be well left for a separate PR. The latest tag name can be extracted with

git tag --list --sort=-version:refname -- "v[0-9]*" | head -1

Otherwise, the update of the citation itself looks good, thank you for improving that.

[mhucka]

OK, will do.

I do think it's valuable to automate updates like this, or at least have checks, because values scattered over different files tend to fall out of sync over time. Eventually when we revise the release workflow, it could be made part of that. For now, a ci-daily is a good idea.