Add badges, update workflows & names #24

[MarcoHuebner]

Added the first few badges and a rudimentary version of test coverage, which requires a pull request to update. Will update iteratively to receive a "cleaner" version for badges containing numbers that need to be extracted from files in assets.

Let's discuss some details on which badges might be interesting and which ones are superfluous in the next meeting.

Resolves #24

[MarcoHuebner]

Update: Doesn't work as intended due to missing coverage.json file upload.

Java and JVM languages only! Other non-third party (but Marketplace extension) workflow: jacoco badge generator

  - name: Generate JaCoCo Badge
     uses: cicirello/jacoco-badge-generator@v2
     with:
       jacoco-csv-file: assets/jacoco/jacocoTestReport.csv
       badges-directory: assets/jacoco

Comparably less fancy Marketplace Action for Python Coverage

Edit: TODO: Write to artifacts, skim Medium & co. tutorial, and investigate community extensions to implement & finish a lightweight basic solution

[MarcoHuebner]

Update: Copied setup from coverage repository, using reports uploaded to GH pages

TODO: Upload test coverage reports to GH-pages, activate upload only on push to main

[MarcoHuebner]

Can be merged