improve importing demos

Author: Borda

src/lightning/pytorch/demos/__init__.py

@@ -1,2 +1,15 @@
-from lightning.pytorch.demos.lstm import LightningLSTM, SequenceSampler, SimpleLSTM  # noqa: F401
-from lightning.pytorch.demos.transformer import LightningTransformer, Transformer, WikiText2  # noqa: F401
+from lightning.pytorch.demos.boring_classes import BoringDataModule, BoringModel, DemoModel
+from lightning.pytorch.demos.lstm import LightningLSTM, SequenceSampler, SimpleLSTM
+from lightning.pytorch.demos.transformer import LightningTransformer, Transformer, WikiText2
+
+__all__ = [
+    "LightningLSTM",
+    "SequenceSampler",
+    "SimpleLSTM",
+    "LightningTransformer",
+    "Transformer",
+    "WikiText2",
+    "BoringModel",
+    "BoringDataModule",
+    "DemoModel",
+]