docs: def generate_lines(self, infile):
          """ Split file into lines
  
          return dict with line=input, depth=n
          """
          pound = '#'
          
          for line in infile:
  
              heading = self.hash_count(line)
  
              indent = self.hash_count(line, pound=' ')
  
              yield dict(line=line.strip(),
                         heading=heading,
                         indent=indent)