code: def _apply_line_rules(self, markdown_string):
          
          all_violations = []
          lines = markdown_string.split("\n")
          line_rules = self.line_rules
          line_nr = 1
          ignoring = False
          for line in lines:
              if ignoring:
                  if line.strip() == '<!-- markdownlint:enable -->':
                      ignoring = False
              else:
                  if line.strip() == '<!-- markdownlint:disable -->':
                      ignoring = True
                      continue
  
                  for rule in line_rules:
                      violation = rule.validate(line)
                      if violation:
                          violation.line_nr = line_nr
                          all_violations.append(violation)
              line_nr += 1
          return all_violations
docs: Iterates over the lines in a given markdown string and applies all the enabled line rules to each line