add several input examples

app.py

@@ -81,6 +81,11 @@ demo = gr.Interface(
     ],
     title="Naturalness Prediction",
     description="Enter SMILES string to get the prediction from the fine-tuned ChemBERTa model.",
+    examples=[
+        ["CN1C=NC2=C1C(=O)N(C(=O)N2C)C"],  # Caffeine - natural product
+        ["CC(C)NCC(COC1=CC=C(C=C1)COCCOC(C)C)O"],  # Atenolol - synthetic
+        ["CC1=C(C(CCC1)(C)C)C=CC(=CC=CC(=CC(=O)O)C)C"]  # Retinoic acid - natural product
+    ],
     flagging_mode="never"
 )