I doubt video documentation is a great idea. Text is more clear, you can read at your own pace, click links, search, etc. Videos are honestly a poor way to learn to code. For art, it's good, but really you need to get comfortable with reading and writing if you want to be a programmer. Also, the documentation is under source control and many people contribute. It's not one person that writes all the docs. So if there is a mistake in a video, or the API changes, or you want to add one little thing, it's a huge problem.