cmake build targets for vcpkg

[Caldfir]

I have created a cmake buildfile that created build-targets for TinySoundFont. I am using this to allow the library dependency to be managed by vcpkg: https://github.com/Caldfir/vcpkg/tree/tinysf

[schellingb]

I don't know much about CMake but I feel like it's not in the spirit of single-file libraries as popularized by the stb libraries by Sean Barrett. Having such a build-system specific file in the repository would make it seem like that is a requirement. The beauty of single-file libraries is that anyone can integrate them the way it fits ones coding style. Be that with a complex build system or just compiling a single .c file via the command line. There is no recommended way how to integrate them because every way is valid :-)
We could have a CMake thing for the examples (just like we have Visual Studio project files) but I'm not sure how that would be superior than the gcc/clang shell scripts we already have for the examples.