message: Updated doc based on review comments
diff: @@ -47,7 +47,7 @@ REGISTER_OP("_MklNativeConv3D")
  MKL version of Conv3D operator that does not depend on layout propagation.
  Uses oneDNN APIs to perform 3D convolution.
  -NOTE Do not invoke this operator directly in Python. Graph rewrite pass is
  +*NOTE*: Do not invoke this operator directly in Python. Graph rewrite pass is
  expected to invoke these operators.
  )doc");
  @@ -74,7 +74,7 @@ MKL version of Convolution3D backward input op that does not depend on layout
  propagation. Uses oneDNN APIs to compute the gradients of convolution with
  respect to the input.
  -NOTE Do not invoke this operator directly in Python. Graph rewrite pass is
  +*NOTE*: Do not invoke this operator directly in Python. Graph rewrite pass is
  expected to invoke these operators.
  )doc");
  @@ -100,7 +100,7 @@ MKL version of Conv3DBackpropFilter op that does not depend on layout
  propagation. Uses oneDNN APIs to compute the gradients of convolution
  with respect to the filter.
  -NOTE Do not invoke this operator directly in Python. Graph rewrite pass is
  +*NOTE*: Do not invoke this operator directly in Python. Graph rewrite pass is
  expected to invoke these operators.
  )doc");
  