text: Title: Change the example in the documentation of Transpose
  Body: TL;DR: 
  
  The ONNX documentation for operator `Transpose` does not remove an ambiguity.  The current example is 
  
  > For example, when perm=(1, 0, 2), given an input tensor of shape (1, 2, 3), the output shape will be (2, 1, 3).
  
  I propose to replace it with
  
  > For example, when perm=(2, 0, 1), given an input tensor of shape (1, 2, 3), the output shape will be (3, 1, 2).
  
  Long version:
  
  Applying the permutation `perm` over a tensor of shape `(d1,...,dk)` leads to a tensor of shape `(d'1,...,d'k)` such that `d'i = d(perm[i])`.  Another (slightly less natural but reasonable) interpretation would be to assume instead that `d'(perm[i]) = di`. (Indeed, that's the inverse permutation of `perm`).  The current example from the documentation is such that it is its own inverse, which means that it does not disambiguate the two interpretations.  In the example I propose, the incorrect interpretation would lead to a tensor of shape (2,3,1).  Hence, the example is more informative.