Add a doc which details how to add a library to CE
Add a doc which details how to add a library to CE

dkm/gcc-explorer,mattgodbolt/gcc-explorer,dkm/gcc-explorer,dkm/gcc-explorer,dkm/gcc-explorer,mattgodbolt/gcc-explorer,mattgodbolt/gcc-explorer,mattgodbolt/compiler-explorer,mattgodbolt/compiler-explorer,mattgodbolt/compiler-explorer,dkm/gcc-explorer,dkm/gcc-explorer,mattgodbolt/gcc-explorer,dkm/gcc-explorer,dkm/gcc-explorer,mattgodbolt/compiler-explorer,mattgodbolt/compiler-explorer,mattgodbolt/compiler-explorer,mattgodbolt/compiler-explorer,dkm/gcc-explorer,mattgodbolt/gcc-explorer,mattgodbolt/compiler-explorer