Switch `<>` back to `[]`

Here we go.

Thoughts?
After the first sentence, this is pure subjectiveness and not distinct from the earlier points.

What *is* of note here is this. At the time when Rust changed from `[]` to `<>`, there was no known precedent in a C-style language for `[]`-generics: C++ and Java, for example, used `<>`. Since then, `[]` has been adopted in at least one fairly popular language, Scala.