[WIP] add media section with p.ex. videos

[andife]

I would find it very helpful to have a media section on the homepage.
With links to the Community Days and to other conference contributions.

Then I could imagine a link to Arxiv and google scholar to onnx articles.
Or only a selection of p.ex. 10

Regarding videos I would find something like https://pyvideo.org/ exciting. I could imagine to contribute the corresponding json. But maybe hosting something like that is also a bit more work.

Signed-off-by: andife [email protected]