Function detect_example_reference_ranges 

pub fn detect_example_reference_ranges(
    content: &str,
    marker_ranges: &[ByteRange],
) -> Vec<ByteRange>

Detect Pandoc example reference ranges ((@label) not at line start).

Excludes positions whose start byte appears in marker_ranges (those are line-start markers, not references). The caller must pass the already-computed result of detect_example_list_marker_ranges so the marker regex is not executed a second time.