In fact, the only area I've been struggling with are "Concepts" because they have less clear boundaries for the right amount of detail.
Here is what I've been working on: https://github.com/super-productivity/super-productivity/wik...
In my case right now, our users are civil engineers, they just want to be able to use our software to model the environment. They really don't want to become an expert programmer on top of that.
They just want to be able to build their thing, like a bridge, so they can make money, and plug numbers into our software to do that.
It's like making a hammer, the documentation needed for forging a hammer out of steel will be radically different from using the hammer to build a house or doing ortho surgery.