Figure out what to test and how

[0gust1]

The actual project has a test execution pipeline that is ready and hooked into the CI.

Example tests are present (and running), but they don't add much value right now (phony/placeholder tests).

• playwright is ready for e2e tests
• vitest is ready for Unit/integration tests

Ideally, E2E tests should be implemented as soon as possible, when the functional/feature coverage of the library would be clearer.

Right now I guess that the e2e testing would be roughly:

• load a showcase website page
• target an example, click some UI controls & do things
• access the component's Molstar instance and assert the actions effects.
• possibly take screenshots and compare with previous run (not fan of theses approaches, very brittle in practice)