Whilst there is some good documentation on the Symfony Config component there isn’t an obvious example to get you started. Here is a simple way (there is much more you can do) to get started using the component as a standalone, without Symfony for example.
I don’t get why we need a TreeBuilder
isn’t it supposed to parse the Yaml file and do the job based on the parsed config file?
Whats is the goal of the TreeBuilder?