lib/amber/render/table_of_contents.rb
def strip_html_tags(html)
      Nokogiri::HTML::DocumentFragment.parse(html, 'UTF-8').children.collect{|child| child.inner_text}.join
    end
def strip_html_tags(html)
      Nokogiri::HTML::DocumentFragment.parse(html, 'UTF-8').children.collect{|child| child.inner_text}.join
    end
removes all html markup