Add anchors link to the showcase list

[jboix]

Description

As a user, I want to have anchor links for each showcase on the demo page so that I can directly link to a specific showcase. This will make it easier to share and navigate to a particular showcase without having to scroll through the entire list.

Acceptance criteria

• Each showcase in the list has a unique anchor link that can be copied and shared.
• (Optional) An index or table of contents is added containing links to each showcase.
• Clicking an anchor link smoothly scrolls to the corresponding showcase section.