function escapeAndHighlightCode() {
  // https://github.com/mathiasbynens/he#heescapetext
  let code = document.querySelector('pre code');
  code.innerHTML = he.escape(code.innerHTML);

  // https://highlightjs.org/
  hljs.highlightBlock(code);
}

window.onload = function() {
  escapeAndHighlightCode();
};