update documentation for missing attributes and properties

Hi, I noticed the attribute saving_managed_mode is not present in saving attributes doc section

In the C++ API, I found https://lima1.readthedocs.io/en/latest/cpp_api.html#_CPPv4N4lima8CtSaving14setManagedModeE11ManagedMode so I imagine this is the same.

Cheers,

Philippe.