cmake: add some small comments to point out whats being done
cmake: add some small comments to point out whats being done

godbyk/spdlog,godbyk/spdlog,hunter-packages/spdlog,COMBINE-lab/spdlog,COMBINE-lab/spdlog,hunter-packages/spdlog,COMBINE-lab/spdlog,hunter-packages/spdlog,godbyk/spdlog