message: Fix the shape of the outcome in the example code.
  The toy language uses element-wise multiplication. Transposing and multiplying
  two tensors with shape <2, 3> gives a tensor with shape <3, 2>.
  Closes
  COPYBARA_INTEGRATE_REVIEW=https://github.com/tensorflow/mlir/pull/227 from ombre5733:toy-ch1-docu-fix
diff: @@ -86,15 +86,15 @@ def main() {
  var b<2, 3> = [1, 2, 3, 4, 5, 6];
  # This call will specialize `multiply_transpose` with <2, 3> for both
  - # arguments and deduce a return type of <2, 2> in initialization of `c`.
  + # arguments and deduce a return type of <3, 2> in initialization of `c`.
  var c = multiply_transpose(a, b);
  # A second call to `multiply_transpose` with <2, 3> for both arguments will
  - # reuse the previously specialized and inferred version and return `<2, 2>`
  + # reuse the previously specialized and inferred version and return <3, 2>.
  var d = multiply_transpose(b, a);
  - # A new call with `<2, 2>` for both dimensions will trigger another
  - # specialization of `multiply_transpose`.
  + # A new call with <3, 2> (instead of <2, 3>) for both dimensions will
  + # trigger another specialization of `multiply_transpose`.
  var e = multiply_transpose(c, d);
  # Finally, calling into `multiply_transpose` with incompatible shape will
  