Move class mentioned in refactoring docs doesn't seem to actually exist #794

Description

The docs on refactorings mention a Move class to be found somewhere in the rope.refactor package and suggest the user instantiate it like so:

mover = Move(project, resource, offset)

But this class doesn't seem to exist anywhere under rope.refactor.

Instead, there are various more specific classes like MoveMethod or MoveModule, plus a helper function create_move whose signature seems to match that of the Move class currently mentioned in the docs.

So the docs should probably be updated to refer to create_move instead.