Possibly incorrect README

[Warfields]

The Example in the README does not make sense to me, but I might be missing something. Specifically, the foo.baz == true example expression. Nowhere else in the example does baz appear, and foo appears twice. First, in the struct tags. Second, in the map. I think that the Z field may have been mislabeled in the example, because foo.baz == true evaluating to true would make sense if Z was labeled as baz.

The correction would be as follows:

type Example struct {
   // ...
   Z bool `bexpr:"foo"`
   // ...
}

Goes to

type Example struct {
   // ...
   Z bool `bexpr:"baz"`
   // ...
}

If I'm not missing anything and this is actually correct, I can open a quick PR to fix this.