added documentation for Assembly.save() param mode (#1458)

Author: ZTThomasOberthanner

cadquery/assembly.py

@@ -464,6 +464,7 @@ def save(
 
         :param path: Path and filename for writing.
         :param exportType: export format (default: None, results in format being inferred form the path)
+        :param mode: STEP only - See :meth:`~cadquery.occ_impl.exporters.assembly.exportAssembly`.
         :param tolerance: the deflection tolerance, in model units. Only used for glTF, VRML. Default 0.1.
         :param angularTolerance: the angular tolerance, in radians. Only used for glTF, VRML. Default 0.1.
         :param \**kwargs: Additional keyword arguments.  Only used for STEP, glTF and STL.