Improve kwargs documentation

[sergisiso]

We had the same problem on the PSyIR Nodes and Symbols kwargs, and the Transformations options which are passed to the super class. I don't like having them duplicated as we never check them when they are updated, or when new arguments added to the subclasses, and would be quite hard to review.

Adding a link to the super() is a good and simple solution (which some IDEs, static type tools may be able to follow).

There is a more complex solution of programmatically modifying the __doc__ to include the BASE.__doc__ or even spit __doc__ to separate the kwargs so that they can be included in the subclass docsting, but this may be over-engineering it, and probably not for this PR.

Originally posted by @sergisiso in #2692 (comment)