Opensource.com - https://opensource.com/article/18/4/documentation-pitfalls-goofy
No matter what type of project you’re working on, you can’t expect users to fully understand it on their own. That’s where documentation comes in. Docs can be anything from simple procedures to thorough user stories. Sure, a web UI can sometimes speak for itself (and the best ones do), but I’m sure you’ve seen tales of readers questioning basic UI paths or squirming about doing anything on the command line.
This is why creating documentation—even for the most basic of topics—is important for users.