message: Updated the TF documentation to include limitations of ipu.optimizers
  Summary: Fixes T36103
  Test Plan: Built doc locally
  Reviewers: jamiep, #tensorflow, simonl, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, markf
  Subscribers: samuelh, markf, grahamh
  Maniphest Tasks: T36103
diff: @@ -267,37 +267,39 @@ In addition to the `tensorflow.python.ipu.optimizers` namespace, it is also poss
  :width: 100%
  :widths: 45,55
  - +---------------------------------------------+------------------------------------------------------------------+
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  | Optimizer | Alternative namespaces |
  - +=============================================+==================================================================+
  - | CrossReplicaOptimizer | tensorflow.python.ipu.cross_replica_optimizer |
  + +================================================================================================+==================================================================+
  + | :class:`~tensorflow.python.ipu.optimizers.CrossReplicaOptimizer` | tensorflow.python.ipu.cross_replica_optimizer |
  | | |
  | | tensorflow.python.ipu.optimizers.cross_replica_optimizer |
  - +---------------------------------------------+------------------------------------------------------------------+
  - | CrossReplicaGradientAccumulationOptimizer | tensorflow.python.ipu.gradient_accumulation_optimizer |
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  + | :class:`~tensorflow.python.ipu.optimizers.CrossReplicaGradientAccumulationOptimizer` | tensorflow.python.ipu.gradient_accumulation_optimizer |
  | | |
  | | tensorflow.python.ipu.optimizers.gradient_accumulation_optimizer |
  - +---------------------------------------------+------------------------------------------------------------------+
  - | CrossReplicaGradientAccumulationOptimizerV2 | tensorflow.python.ipu.gradient_accumulation_optimizer |
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  + | :class:`~tensorflow.python.ipu.optimizers.CrossReplicaGradientAccumulationOptimizerV2` | tensorflow.python.ipu.gradient_accumulation_optimizer |
  | | |
  | | tensorflow.python.ipu.optimizers.gradient_accumulation_optimizer |
  - +---------------------------------------------+------------------------------------------------------------------+
  - | GradientAccumulationOptimizer | tensorflow.python.ipu.gradient_accumulation_optimizer |
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  + | :class:`~tensorflow.python.ipu.optimizers.GradientAccumulationOptimizer` | tensorflow.python.ipu.gradient_accumulation_optimizer |
  | | |
  | | tensorflow.python.ipu.optimizers.gradient_accumulation_optimizer |
  - +---------------------------------------------+------------------------------------------------------------------+
  - | GradientAccumulationOptimizerV2 | tensorflow.python.ipu.gradient_accumulation_optimizer |
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  + | :class:`~tensorflow.python.ipu.optimizers.GradientAccumulationOptimizerV2` | tensorflow.python.ipu.gradient_accumulation_optimizer |
  | | |
  | | tensorflow.python.ipu.optimizers.gradient_accumulation_optimizer |
  - +---------------------------------------------+------------------------------------------------------------------+
  - | MapGradientOptimizer | tensorflow.python.ipu.map_gradient_optimizer |
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  + | :class:`~tensorflow.python.ipu.optimizers.MapGradientOptimizer` | tensorflow.python.ipu.map_gradient_optimizer |
  | | |
  | | tensorflow.python.ipu.optimizers.map_gradient_optimizer |
  - +---------------------------------------------+------------------------------------------------------------------+
  - | ShardedOptimizer | tensorflow.python.ipu.sharded_optimizer |
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  + | :class:`~tensorflow.python.ipu.optimizers.ShardedOptimizer` | tensorflow.python.ipu.sharded_optimizer |
  | | |
  | | tensorflow.python.ipu.optimizers.sharded_optimizer |
  - +---------------------------------------------+------------------------------------------------------------------+
  + +------------------------------------------------------------------------------------------------+------------------------------------------------------------------+
  +
  +.. note:: The `ipu.optimizers` optimizer classes can only be used with subclasses of `tensorflow.compat.v1.train.Optimizer`.
  .. automodule:: tensorflow.python.ipu.optimizers
  :members: CrossReplicaOptimizer, CrossReplicaGradientAccumulationOptimizer, CrossReplicaGradientAccumulationOptimizerV2, GradientAccumulationOptimizer, GradientAccumulationOptimizerV2, MapGradientOptimizer, ShardedOptimizer
  