ideas and resources on user assistance/help documentation needed

For my site, I'd like to implement a state-of-the-art user assistance/help documentation where I would like to have quick info (few text) and visual content (like gif/image) to give visitors a good and easy to consume user experience (e.g. what Apple does here is great https://help.apple.com/macOS/mojave/mac-basics). Yet, my researches have not been very successful regarding "user documentation techniques). Here, I'm not interested in how to write, it's more how to implement based on e.g. a framework/tool that's already there for this (help documentation) purpose. Can you point me to a resource/info where I can get started quickly. Thx