add CMake option to toggle doxygen documentation
add CMake option to toggle doxygen documentation

dean0x7d/cppformat,lightslife/cppformat,mojoBrendan/fmt,cppformat/cppformat,wangshijin/cppformat,Jopie64/cppformat,Jopie64/cppformat,wangshijin/cppformat,alabuzhev/fmt,Jopie64/cppformat,alabuzhev/fmt,dean0x7d/cppformat,lightslife/cppformat,mojoBrendan/fmt,dean0x7d/cppformat,cppformat/cppformat,cppformat/cppformat,wangshijin/cppformat,alabuzhev/fmt,mojoBrendan/fmt,lightslife/cppformat