`surround` is poorly named

Surrounding means to put stuff all around.

From that, I'd infer that `surround a [b, c, d]` means either `a b c d a`, or `a b a c a d a`, but definitely not `b a c a d`, where `b` and `d` are not "surrounded by `a`s.

The standard library use words like `intersperse` or `intercalate`, which imply much better the idea of putting things "in between" other things, rather than all around.