Landing Pages for Theme & Plugin Developers

I could help, but I’m not much of a writer. I find it hard to get into the user mindset, since I know more (even after years of answering forum questions).
But starting with something similar to the WP Theme Developer Handbook would be good. There are a few missing topics in there, too.

Thanks for your response. Please bear with me for the following questions, because I am not a developer:

You mention the WP Theme Developer Handbook. Is this an open source document?
If it is open source, is there any reason why we can’t fork it and adapt it to CP?

If that’s possible, I think it might be a good start, rather than trying to reinvent the wheel.

Again – thank you!

Yes, there has been discussion in the WP docs channel about making the license for the various documents clear. I don’t know if they have put the license somewhere or not (yet).
They already have user docs for the editor, donated from wordpress.com, so this has come up.