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/mixins/post-ui.pug

@@ -18,7 +18,7 @@ mixin postUI(posts)
         .article-meta-wrap
           if (is_home() && (article.top || article.sticky > 0))
             span.article-meta
-              i.fas.fa-thumbtack.article-meta__icon.sticky
+              i.fas.fa-thumbtack.sticky
               span.sticky= _p('sticky')
               span.article-meta__separator |
           if (theme.post_meta.page.date_type)
@@ -42,7 +42,7 @@ mixin postUI(posts)
           if (theme.post_meta.page.categories && article.categories.data.length > 0)
             span.article-meta
               span.article-meta__separator |
-              i.fas.fa-inbox.article-meta__icon
+              i.fas.fa-inbox
               each item, index in article.categories.data
                 a(href=url_for(item.path)).article-meta__categories #[=item.name]
                 if (index < article.categories.data.length - 1)
@@ -50,11 +50,42 @@ mixin postUI(posts)
           if (theme.post_meta.page.tags && article.tags.data.length > 0)
             span.article-meta.tags
               span.article-meta__separator |
-              i.fas.fa-tag.article-meta__icon
+              i.fas.fa-tag
               each item, index in article.tags.data
                 a(href=url_for(item.path)).article-meta__tags #[=item.name]
                 if (index < article.tags.data.length - 1)
                   span.article-meta__link #[='•']
+          
+          mixin countBlockInIndex
+            - needLoadCountJs = true
+            span.article-meta
+              span.article-meta__separator |
+              i.fas.fa-comments
+              if block
+                block
+              span.article-meta-label= ' ' + _p('card_post_count')
+          
+          if theme.comments.card_post_count
+            case theme.comments.use[0]
+              when 'Disqus'
+              when 'Disqusjs'
+                +countBlockInIndex
+                  a(href=full_url_for(link) + '#disqus_thread')
+              when 'Valine'
+                +countBlockInIndex
+                  a(href=url_for(link) + '#post-comment' itemprop="discussionUrl")
+                    span.valine-comment-count(data-xid=url_for(link) itemprop="commentCount")
+              when 'Waline'
+                +countBlockInIndex
+                  a(href=url_for(link) + '#post-comment')
+                    span.waline-comment-count(id=url_for(link))
+              when 'Twikoo'
+                +countBlockInIndex
+                  a.twikoo-count(href=url_for(link) + '#post-comment')
+              when 'Facebook Comments'
+                +countBlockInIndex
+                  a(href=url_for(link) + '#post-comment')
+                    span.fb-comments-count(data-href=urlNoIndex(article.permalink))
 
         //- Display the article introduction on homepage
         case theme.index_post_content.method