breaking changes: 適配 disqusjs 3.0

fix: 修復首頁文章 valine 評論數只顯示第一篇的 bug
fix: 修復子目錄下，第三方插件本地資源無法加載的 bug closed #908
fix: 評論系統開啟時 busuanzi 的 page_pv 不顯示的 bug closed #902
fix: 修復 pjax 下，使用 mermaid 跳轉會重新加載的 bug

layout/includes/third-party/pjax.pug

@@ -3,7 +3,7 @@ if theme.pjax.exclude
   each val in theme.pjax.exclude
     - pjaxExclude = pjaxExclude + `:not([href="${val}"])`
 
-- let pjaxSelectors = ['title','#config-diff','#body-wrap','#rightside-config-hide','#rightside-config-show','.js-pjax']
+- let pjaxSelectors = ['head > title','#config-diff','#body-wrap','#rightside-config-hide','#rightside-config-show','.js-pjax']
 
 - let choose = theme.comments.use
 if choose
@@ -47,6 +47,7 @@ script.
     const $bodyClassList = document.body.classList
     $bodyClassList.contains('read-mode') && $bodyClassList.remove('read-mode')
 
+    typeof disqusjs === 'object' && disqusjs.destroy()
   })
 
   document.addEventListener('pjax:complete', function () {