I don’t know if anyone else has run into this, but: I have a home server I used in lieu of Google et al, which runs in part on Docker containers. Trying to set up SearXNG and Gluetun recently I had a hell of a time getting the settings right because a few critical pieces of the yml file weren’t noted in the documentation. I had to check third party examples and eventually figure it out.
Is this a common experience? Someone say “yes” and validate my experience . . . 
I can not say for your specific case, but it is unfortunately common for documentation to have errors or omissions.
That is not only a Linux problem… it is more that programmers are lousy document writers… with some noted exceptions like Kernighan and Ritchie.
In my limited experience with Docker - it appears to complicate the simple with minimal value-added.
The added value is portability. You can move a docker container to any Linux distro and it will work… because it carries the software’s environment with it.
Actually you do not move the container, you only need to move the Dockerfile.
Sure it is complicated. It took me ages to learn how to build a docker container, and I needed help.
Docker is far more popular in commercial systems than in home systems. That is because it offers a way to freeze something so that it will always work.