message: ipu_estimator: Fix link and typo in docs
  Summary: Ref. T20167
  Reviewers: #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, georgep
  Maniphest Tasks: T20167
diff: @@ -1202,7 +1202,7 @@ class IPUEstimator(_IPUEstimatorBase):
  Args:
  model_fn: The model function. Refer to
  - https://www.tensorflow.org/guide/custom_estimators#write_a_model_function
  + https://github.com/tensorflow/docs/blob/master/site/en/r1/guide/custom_estimators.md#write-a-model-function
  for details on how to write this function.
  model_dir: Directory to save model parameters, graph and etc. This can
  also be used to load checkpoints from the directory into an estimator to
  @@ -1223,7 +1223,7 @@ class IPUEstimator(_IPUEstimatorBase):
  train_batch_size: If not None, an int representing the global training
  batch size. This global batch size is transformed to a local batch size
  passed as `params['batch_size']` to the `input_fn` and `model_fn` during
  - training. Must be divisble by the number of replicas multiplied by the
  + training. Must be divisible by the number of replicas multiplied by the
  number of distributed workers.
  eval_batch_size: If not None, an int representing the global evaluation
  batch size. Same behaviour as train_batch_size, only during evaluation.
  