Documentation bug in strategy 2 (default)

[jaburgoyne]

The documentation describes the local-to-best update (strategy 2, the default) as
$$v_{i,g} = old_{i,g} + (best_g - old_{i,g}) + x_{r0,g} + F \cdot (x_{r1,g} - x_{r2,g})$$
This doesn’t really make sense or seem to match how local-to-best is described in the literature. (I’m quite new to differential evolution, though, and so please correct me if I’m wrong there.)

But more importantly, the documentation also doesn’t match the code. The update rule should be
$$v_{i,g} = old_{i,g} + F \cdot (best_g - old_{i,g}) + F \cdot (x_{r1,g} - x_{r2,g})$$