breaking changes: 刪除 hide_sidebar_menu_child 配置，改為直接在 menu 配置 close #640

feat: sidebar menu 點擊展開不再限制只能點擊按鈕 #640
feat: TWIKOO 評論圖片添加 lightbox
feat: 升級 facebook comment js 到 v11
fix: 修復可能導致相關文章鏈接出錯的bug #549
improvement: 調整代碼框 ocean theme 下滾動條顏色 close #651
improvement: 當圖片沒有 figcaption 時，不會添加 figcaption 代碼
improvement: 代碼優化

layout/includes/third-party/comments/utterances.pug

@@ -13,13 +13,13 @@ script.
   }
 
   function utterancesTheme () {
-    if (document.querySelector('.utterances-frame')) {
+    const iframe = document.querySelector('.utterances-frame')
+    if (iframe) {
       const theme = document.documentElement.getAttribute('data-theme') === 'dark' ? '#{theme.utterances.dark_theme}' : '#{theme.utterances.light_theme}'
       const message = {
         type: 'set-theme',
         theme: theme
       };
-      const iframe = document.querySelector('.utterances-frame');
       iframe.contentWindow.postMessage(message, 'https://utteranc.es');
     }
   }