Where is the documentation for theme files?
The documentation for theme files is very poor. I spent over an hour at https://api.kde.org/frameworks/syntax-highlighting/html/index.html (which I also found uninformative) before realising that I was looking at the wrong information to create theme files. The post at https://kate-editor.org/post/2020/2020-09-18-submit-a-ksyntaxhighlighting-color-theme/ likewise encourages us to submit themes but provides no guidance on how to create .theme files.
If the JSON syntax is inherited from Qt, then there should be a link to Qt's documentation indicating this. Otherwise, something other than reverse-engineering existing theme files would be helpful. It is also not clear how we can "install" our own theme files in KDE. Into which XDG directory should such files go, and where can I find the default theme definitions files from which to work (in my installation, not the source).
With thanks,