update app.py

app.py

@@ -18,7 +18,7 @@ gr.Interface(
       headers=["docno", "text", "querygen"],
       datatype=["str", "str", "str"],
       row_count=0,
-      col_count=0,
+      col_count=3,
     ),
     title="pyterrier_doc2query",
 ).launch()