[FEAT] Reference this demo in the bpmn-visualization-examples live environment

[tbouffard]

This requires #36

In the bpmn-visualization-examples repository, reference the demo in

• [ ] README : demos paragraph
• [ ] HTML home page: add a card in the demo section. See if we can direct for both the demo and the gh repository

See also https://github.com/process-analytics/bpmn-visualization-tutorial-getting-started/issues/24