To add this library to your project, simply add these two lines to your CMakeLists.txt:
add_subdirectory(path/to/wants_dark_theme)
target_link_libraries(${PROJECT_NAME} PRIVATE wants_dark_theme::wants_dark_theme)
Then include it as:
#include <wants_dark_theme/wants_dark_theme.hpp>
Simply use "tests/CMakeLists.txt" to generate a project, then run it.
If you are using VSCode and the CMake extension, this project already contains a .vscode/settings.json that will use the right CMakeLists.txt automatically.