Update readme.md

Benchmarks/DL/readme.md

@@ -1,4 +1,5 @@
 Use the run.bat under the folder mnist to autotune the mnist.
 - problem.py: define the parameter space using configspace
 - mnist_mlp.py: the original deep learning code
+- mnist-omp.py: the OpenMP version of mnist
 - dlp.py: the parameterized code (code mold)