Switch `<>` back to `[]`

Here we go.

Thoughts?
@TheHydroImpulse You should specify *on most keyboards*; you simply can’t make such assertions without appropriate guard conditions.

@kballard On the standard US English keyboard, `[]` don’t require the `Shift` modifier to enter them whereas `<>` do. The impact of this is reduced for `[` as it will normally be followed by an uppercase letter, incidentally, but it won’t for `['a` and it won’t for `]` unless the last character was also uppercase. This, I presume, is what you are referring to here: for `<T>` you can just hold the Shift key for all three characters, whereas with `[T]` you can’t. I accept this case. Still, in most cases I find `[]` a little easier to type than `<>`.