pub fn iter_with_line_column(
    s: &str,
) -> impl Iterator<Item = (char, usize, usize, LineColumn)> + '_ {
    iter_with_line_column_from(s, LineColumn { line: 1, column: 0 })
}
Iterate over annotated chars starting from line 1 and column 0 assuming `s`
starts there.
doc-chunks/src/util.rs