I am eager to know which kind of learning rule is used in the package for simulating this example?
Is it the simultaneously supervised and unsupervised one (hPES)?
If so, what can we learn from this example?
There is no online learning in that example. If you are wondering how the weights are computed, in that case it is done using the Neural Engineering Framework (NEF), which you can read more about here.
There is no online learning in that example either (none of the SPA examples have learning in them).
You can find all of the Nengo learning examples here Examples — Nengo 4.0.1.dev0 docs. That includes supervised (PES) and unsupervised (Voja, Oja, BCM) learning. hPES refers to a combination of those rules (e.g. PES + BCM).
You can find some previous discussion of reinforcement learning (including links to examples and papers) in these threads: