message: Improve connection_type docstring
  Summary: For T25998, just add a little more info about connection type in TF
  Reviewers: jamiep, #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, georgep
  Maniphest Tasks: T25998
diff: @@ -1221,7 +1221,11 @@ def select_ipus(opts, indices):
  def set_ipu_connection_type(opts, connection_type=None, ipu_version=None):
  - """ Configure when to attach to the device.
  + """ Configure when to attach to the device. For example, you can use
  + this to compile and cache a program without attaching to an IPU,
  + and then later run on a real IPU device without recompiling.
  + Setting the connection type doesn't impact the ability to profile
  + a model.
  .. code-block:: python
  @@ -1238,8 +1242,9 @@ def set_ipu_connection_type(opts, connection_type=None, ipu_version=None):
  connection_type: One of `DeviceConnectionType`.
  Defaults to `DeviceConnectionType.ALWAYS` if None.
  - ipu_version: Version of the IPU hardware used. Required if the
  - `connection_type` provided is `DeviceConnectionType.NEVER`.
  + ipu_version: Version of the IPU hardware used (int). E.g. 1 for Mk1
  + and 2 for Mk2. Required if the `connection_type`
  + provided is `DeviceConnectionType.NEVER`.
  Returns:
  The IpuOptions configuration protobuf.
  """
  