feat: 增加首頁評論數顯示

fix: 修復點擊toc後，滾動完toc的highlight在點擊的上一個元素
fix: 修復打賞按鈕Hover的bug close #473
improvement: 友情鏈接界面增加title顯示（top_img設為false時）
improvement: 優化toc顯示，當向上滾動時，導航欄不會遮擋 toc close #472
improvement: 升級facebook comment sdk版本

layout/includes/third-party/card-post-count/valine.pug

@@ -0,0 +1,19 @@
+script.
+  (() => {
+    function loadValine () {
+      function initValine () {
+        let initData = {
+          el: '#vcomment',
+          appId: '#{theme.valine.appId}',
+          appKey: '#{theme.valine.appKey}',
+        }
+        
+        const valine = new Valine(initData)
+      }
+
+      if (typeof Valine === 'function') initValine() 
+      else getScript('!{url_for(theme.CDN.valine)}').then(initValine)
+    }
+
+    window.pjax ? loadValine() : window.addEventListener('load', loadValine)
+  })()