Add explanation to `operator` docs about intentionally excluding short-circuit operators

Following discussion on PEP 824 here about whether a new None-coalescing operator should be added to the operator module in the standard library it was pointed out that short-circuit operators are intentionally not implemented there (because it’s not possible with a function to perform the short-circuit behaviour). I would like to propose that the docs for operator might benefit from a few lines making it explicit which python operators are not implemented for this reason and why. One can imagin...