Consider using Job Summaries

[malcolmbarrett]

(Sorry to delete the FR template, but this seems like a self-explanatory suggestion!)

GitHub Actions recently added Job Summaries, which might be useful for the workflows here, particularly for package testing.

https://github.blog/2022-05-09-supercharging-github-actions-with-job-summaries/

[Bisaloo]

Related: r-lib/testthat#1621

[gaborcsardi]

PoC here: r-lib/testthat#1635

[gaborcsardi]

Technically this is blocked here, because we need some output from the testing tool (i.e. testthat) that we can use to generate the the job summary.

E.g. testthat could write the test results into a file, and then we could have an action or other code to format that as a job summary. Or testthat could also create the markdown output directly, as in the PoC above.