message: Update README.md and fix code block
diff: @@ -275,6 +275,7 @@ typedef struct Data_{
  int dense[dense_dim];
  int category[sparse_dim];
  } Data;
  +```
  ## Coding Style and Refactor ##
  Default coding style follows Google C++ coding style [(link)](https://google.github.io/styleguide/cppguide.html).
  