Add a link to explain the compilation command

tutorials/embedding/README.md

@@ -21,11 +21,12 @@ rm source-archive.zip
 
 You will need to compile the ops as follows:
 
-``` shell
+```shell
 TF_INC=$(python -c 'import tensorflow as tf; print(tf.sysconfig.get_include())')
 g++ -std=c++11 -shared word2vec_ops.cc word2vec_kernels.cc -o word2vec_ops.so -fPIC -I $TF_INC -O2
 ```
 
+(If you want to know what this is doing, see the tutorial on [Adding a New Op to TensorFlow](https://www.tensorflow.org/how_tos/adding_an_op/#building_the_op_library)).
 Then run using:
 
 ```shell