Add scaffolds to default layer imports.

PiperOrigin-RevId: 288774884

official/nlp/modeling/layers/__init__.py

@@ -20,3 +20,4 @@ from official.nlp.modeling.layers.on_device_embedding import OnDeviceEmbedding
 from official.nlp.modeling.layers.position_embedding import PositionEmbedding
 from official.nlp.modeling.layers.self_attention_mask import SelfAttentionMask
 from official.nlp.modeling.layers.transformer import Transformer
+from official.nlp.modeling.layers.transformer_scaffold import TransformerScaffold

official/nlp/modeling/networks/__init__.py

@@ -15,6 +15,7 @@
 """Networks package definition."""
 from official.nlp.modeling.networks.albert_transformer_encoder import AlbertTransformerEncoder
 from official.nlp.modeling.networks.classification import Classification
+from official.nlp.modeling.networks.encoder_scaffold import EncoderScaffold
 from official.nlp.modeling.networks.masked_lm import MaskedLM
 from official.nlp.modeling.networks.span_labeling import SpanLabeling
 from official.nlp.modeling.networks.transformer_encoder import TransformerEncoder