message: Improve tf.einsum documentation
  Improve tf.einsum documentation to include outer product
diff: @@ -169,7 +169,7 @@ def _enclosing_tpu_context():
  @tf_export('einsum', 'linalg.einsum')
  def einsum(equation, *inputs, **kwargs):
  - """A generalized contraction between tensors of arbitrary dimension.
  + """Contraction over specified indices and outer product for an arbitrary number of tensors.
  This function returns a tensor whose elements are defined by `equation`,
  which is written in a shorthand form inspired by the Einstein summation
  