Function atom_from_cursor

fn atom_from_cursor<'a>(
    arena: &'a Arena<Syntax<'a>>,
    src: &str,
    nl_pos: &LinePositions,
    cursor: &mut TreeCursor<'_>,
    highlights: &HighlightedNodeIds,
    ignore_comments: bool,
) -> Option<&'a Syntax<'a>>

Convert the tree-sitter node at cursor to a difftastic atom.