vine: DaskVine.get has undocumented parameters

[btovar]

From doxygen:

parameter 'scheduling_mode'
parameter 'prune_depth'
parameter 'hoisting_modules'
parameter 'import_modules'

[btovar]

@JinZhou5042 Could you document these ones? Are they related to your changes?

[JinZhou5042]

Yes, some of them are related to the recent changes. I will go through these parameters and document them in the manual by this weekend.