message: Lower case c++1z config
  The `.bazelrc` actually checks for `c++1z` and not `C++1z` (mind the capital `C`) so this should be accounted for in the docs.
diff: # Compiler options:
  # cuda_clang: Use clang when building CUDA code.
  # c++17: Build with C++17 options
  -# C++1z: Build with C++17 options
  +# c++1z: Build with C++17 options
  # avx_linux: Build with avx instruction set on linux.
  # avx2_linux: Build with avx2 instruction set on linux.
  # native_arch_linux: Build with instruction sets available to the host machine on linux
  