Update highlight.js example to latest version.

[gabriel-dahan]

Since highlight-v10, highlight(lang, code) is deprecated, instead use highlight(code, {language: lang})

highlight: function (str, lang) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return hljs.highlight(lang, str).value;
      } catch (err) {}
    }

    try {
      return hljs.highlightAuto(str).value;
    } catch (err) {}

    return ''; // use external default escaping
  }

becomes

highlight: function (str, lang) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return hljs.highlight(str, {language: lang}).value;
      } catch (err) {}
    }

    try {
      return hljs.highlightAuto(str).value;
    } catch (err) {}

    return ''; // use external default escaping
  }