I might be interested, esp. since it claims Python bindings, but documentation appears to be nil. Seriously, nonexistent. A GUI lib surely has an API complex enough to require _some_ kind of reference docs, at least. But the contents of the doc folder[1] are just a joke, most of the files contain single lines, and the .md files are fragments with many "TODO" notes.
So OK maybe I can get some insight reading the code. The "common" folder seems a good place to start[2]. Um, no. Short, generic uninformative filenames ("matrix.c", "control.c") and very few introductory comments. The opposite of "literate programming".
For imgui (https://github.com/ocornut/imgui/) and uklear (https://github.com/vurtun/nuklear), docs are basically unnecessary. You just have to look at the examples/demos and copy pasta. Immediate mode GUIs are great.