breaking changes: algolia 升級至 v4

feat:  本地搜索增加數據庫加載中和搜索中 loading 顯示
feat: 更改文章美化後,列表的顯示效果 closed #693 closed #686
improvement: UI 微調

source/css/_search/local-search.styl

@@ -15,6 +15,9 @@
         color: var(--search-input-color)
         -webkit-appearance: none
 
+    .search-wrap
+      display: none
+
     .local-search__hit-item
       position: relative
       padding-left: 24px