https://github.com/tensorflow/community/pull/16.
In addition to the changes in the doc, I made the following updates (these changes make sense to me and I didn't notice them when compiling the doc):
* deprecate saved_model.builder.SavedModelBuilder - replaced with saved_model.SavedModelBuilder
* deprecate python_io.tf_record_iterator - replaced with io.tf_record_iterator
* deprecate python_io.TFRecordWriter - replaced with io.TFRecordWriter
* move reduce_join to tf.string

PiperOrigin-RevId: 215253944