fn bracketed_targets(s: &str) -> Vec<(&str, &str)>Expand description
The [...] link targets in one line of markdown, as (written, target).
Mirrors the scanner in miniextendr-macros/src/roxygen.rs
(sanitize_roxygen_links): code spans and \[ are skipped, an inline
[text](dest) is no R link, [text][target] has its own target and
[target] is its own.