Possible errata in compute shader article.

[Aurora2500]

In the explanation for local_invocation_index, I believe there is an errata in the explanation code segment shown:

    rowSize = workgroup_size.x
    sliceSize = rowWidth * workgroup_size.y
    local_invocation_index =
          local_invocation_id.x +
          local_invocation_id.y * rowSize +
          local_invocation_id.z * sliceSize

I believe that in the definition of sliceSize, it should be rowSize rather than rowWidth, given that that makes sense here and also that there is no definition for rowWidth anywhere.