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/comments/disqus.pug

@@ -4,7 +4,7 @@ script.
   function loadDisqus () {
     var disqus_config = function () {
       this.page.url = '!{ page.permalink }'
-      this.page.identifier = '!{ page.path }'
+      this.page.identifier = '!{ url_for(page.path) }'
       this.page.title = '!{ disqusPageTitle }'
     };
 
@@ -24,6 +24,10 @@ script.
         (d.head || d.body).appendChild(s);
       })();
     }
+
+    document.getElementById('darkmode').addEventListener('click', () => {
+      setTimeout(() => window.disqusReset(), 200)
+    })
   }
 
   if ('!{theme.comments.use[0]}' === 'Disqus' || !!{theme.comments.lazyload}) {