I don't like this part.
Currently it sets the width of the embedded video to 500 pixels. I'd prefer it was a percentage of the page width instead (i.e. more responsive to different screen sizes). I don't think you can do that easily with sphinxcontrib-video as it currently exists, so maybe we should replace this dependency with a template docstring of the HTML we need to embed in the RST document, so we can have more control over the output result.
Docs: https://github.com/sphinx-contrib/video
This nice to have to-do item came up during development of https://github.com/napari/napari-animation/pull/200
https://github.com/napari/napari-animation/pull/200#issuecomment-1914100665
https://github.com/napari/napari-animation/pull/200#discussion_r1465848115