Can I use a video or a WebM in the CMS as a cover? I would like to have animations on the overview of the articles.
I was able to insert and image from my CMS above my blog entries.
See this section of my website for a demonstration. Click one of the entries to show you how it looks. Christ 2R Culture - Answers To Your Questions
As for how to do it… Notice the twig code from the CMS in the image field.
This is how I handled it in the frontmatter of my markdown file.
I hope this helps! 