Document that CMAKE_BUILD_TYPE will be set by project() and enable_language()
According to #17944, the
enable_language() now init the
I'm not sure I can confirm this everywhere, but at lest with CMake 3.13, Ninja on Windows
CMAKE_BUILD_TYPE is set to Debug. Somehow this is not happening in Ubuntu with CMake 3.13.
Anyway, if that's the expected behavior please document this.