Problem:
In the current Timeline widget, each event must be clicked manually for its associated content (text/image) to appear.
This interaction pattern is not ideal for all learning scenarios — especially in linear or narrative timelines, repeated clicking can be distracting and offers little didactic value.

Suggestion:
Add an option in the Captivate GUI and in the designOption.json to control the behavior:
- Manual (current behavior): The user clicks each event to reveal its content.
- Automatic: The content is always visible.
- For better user experience: The content appears with a smooth fade-in or motion animation when the event enters the viewport.