Format docstring as per ruff

Author: joelostblom

altair/vegalite/v5/api.py

@@ -3823,7 +3823,8 @@ def interactive(
         tooltip: bool = True,
         legend: Union[bool, list] = True,
     ) -> Self:
-        """Add common interactive elements to the chart
+        """
+        Add common interactive elements to the chart.
 
         Parameters
         ----------