Add a presentation section to the organization website

Add a presentation section to the organization website with a list of presentation (which can be extended). Each card with presentation should have title, picture and link to the presentation.

Start by reviewing the organization website and the structure of its existing sections. Add a presentation section with an extensible list of cards, ensuring each card has a title, picture, and presentation link; the work is done when the section renders correctly and additional presentations can be added.

Written by the indexing model from the issue text.