Merge pull request #10992 from apolcyn/doxygen_cpp_nits

doc/PROTOCOL-WEB.md

doc/compression.md

doc/cpp-style-guide.md

doc/fail_fast.md

doc/service_config.md

doc/stress_test_framework.md

...e/grpc++/ext/health_check_service_server_builder_option.h

include/grpc++/ext/proto_server_reflection_plugin.h

include/grpc++/generic/generic_stub.h

include/grpc++/grpc++.h

include/grpc++/health_check_service_interface.h

include/grpc++/impl/codegen/async_stream.h

include/grpc++/impl/codegen/async_unary_call.h

include/grpc++/impl/codegen/call.h

include/grpc++/impl/codegen/call_hook.h

include/grpc++/impl/codegen/client_context.h

include/grpc++/impl/codegen/client_unary_call.h

include/grpc++/impl/codegen/completion_queue.h

include/grpc++/impl/codegen/completion_queue_tag.h

include/grpc++/impl/codegen/config.h