feat: 預設關閉 structured_data

feat: 升級一些項目依賴
feat: 重寫 README.md 和 README_CN.md，改進文檔結構和內容
feat: tags 標籤插件夜間模式調整
feat: 加按鈕懸停效果和動畫
fix: 修復右下角箭頭圖標位置沒有居中的 bug
feat: 增加右下角箭頭和滾動百分比的切換效果
improvement: 優化 tags 頁標籤雲顯示效果
improvement: 整合部分js到 init.js
improvement: 統一 CSS 變數使用，改進主題一致性

source/css/_layout/rightside.styl

@@ -54,19 +54,52 @@
 
   if hexo-config('rightside_scroll_percent')
     #go-up
+      position: relative
+
       .scroll-percent
+        position: absolute
+        top: 0
+        left: 0
         display: none
+        width: 100%
+        height: 100%
+        opacity: 0
+        transition: all .4s cubic-bezier(.4, 0, .2, 1)
+        transform: scale(.8)
+
+      i
+        position: relative
+        z-index: 1
+        width: 100%
+        opacity: 1
+        transition: all .4s cubic-bezier(.4, 0, .2, 1)
+        transform: scale(1)
 
       &.show-percent
         .scroll-percent
           display: block
+          opacity: 1
+          transform: scale(1)
+          animation: fadeInScale .4s ease-out
 
-          & + i
-            display: none
+        i
+          opacity: 0
+          transform: scale(.8)
 
-      &:hover
+      &:hover.show-percent
         .scroll-percent
-          display: none
+          opacity: 0
+          transform: scale(.8)
 
-          & + i
-            display: block
+        i
+          opacity: 1 !important
+          transform: scale(1) !important
+
+@keyframes fadeInScale
+  from
+    opacity: 0
+    transform: scale(.8)
+
+  to
+    opacity: 1
+    transform: scale(1)