title_to_idx

# File railties/guides/rails_guides/indexer.rb, line 61
    def title_to_idx(title)
      idx = title.strip.parameterize.sub(/^\d+/, '')
      if warnings && idx.blank?
        puts "BLANK ID: please put an explicit ID for section #{title}, as in h5(#my-id)"
      end
      idx
    end