docs: def group_lines(lines):
      """Split a list of lines using empty lines as separators."""
      groups = []
      group = []
  
      for line in lines:
          if line.strip() == "":
              groups.append(group[:])
              group = []
              continue
          group.append(line)
  
      if group:
          groups.append(group[:])
  
      return groups