[Epic] More and better project badges

[binkley]

See #506
Merge this and the card @binkley

There are several cards that might involve adding project badges.
We should document as this visibility would be useful to others.

Presently the existing writing is scattered:

• "Leverage unit testing and coverage"
• "Shift security left"
• Can we add badges for each of the toolings the project uses?
• Do each of the quality tools have a badge (possibly 3rd-party) we can use?

Related cards

• CodeQL -- Add CodeQL badge #597
• Code stability -- A badge for build stability #387
• Coverage -- Improve project badges #506

Goals

• Improve project visibility from the code repo front page
• Write on how others reuse our learnings on this
• Consolidate into one place with internal links for navigation ("Getting your project started"? Elsewhere?)

Tech notes

• Earthly needs updating to save relevant files/dirs outside the container -- SAVE ARTIFACT; https://github.com/binkley/kotlin-magic-bus has an example

References

• https://github.com/cicirello/jacoco-badge-generator#jacoco-csv-file

[jwlibby]

CodeQL badge can be found here: