Thx for the wonderful ryml!
Recently, I integrated ryml into my company's projects.It works well, however when I use CPack packaging our project, ryml is always packaged into the final product. We want the packaging to be as lean as possible. Could you help add a custom option that allows users to choose not to install ryml？(If you think this option is necessary but don't have the time, I I would also be happy to pull a merge request if you don't mind.)

e.g. yaml-cpp has YAML_CPP_INSTALL option to help users ignore it's installation.