Make it clearer what we use / don't use in Clang and Clang-Tidy.
Make it clearer what we use / don't use in Clang and Clang-Tidy.

MichaelClerx/libcellml,hsorby/libcellml,nickerso/libcellml,hsorby/libcellml,nickerso/libcellml,MichaelClerx/libcellml,nickerso/libcellml,hsorby/libcellml,cellml/libcellml,nickerso/libcellml,MichaelClerx/libcellml,hsorby/libcellml,cellml/libcellml,cellml/libcellml,cellml/libcellml