Add GitBook theme structure with Traditional Chinese docs

gitbook/components/JumpToTopButton.js

@@ -0,0 +1,28 @@
+/**
+ * 跳轉至網頁頂端
+ * 當畫面往下滑 500 像素後會顯示此元件
+ * @param targetRef 關聯高度的目標 HTML 標籤
+ * @param showPercent 是否顯示百分比
+ * @returns {JSX.Element}
+ * @constructor
+ */
+const JumpToTopButton = ({ showPercent = false, percent, className }) => {
+  return (
+    <div
+      id='jump-to-top'
+      data-aos='fade-up'
+      data-aos-duration='300'
+      data-aos-once='false'
+      data-aos-anchor-placement='top-center'
+      className='fixed xl:right-96 xl:mr-20 right-2 bottom-24 z-20'>
+      <i
+        className='shadow fas fa-chevron-up cursor-pointer p-2 rounded-full border bg-white dark:bg-hexo-black-gray'
+        onClick={() => {
+          window.scrollTo({ top: 0, behavior: 'smooth' })
+        }}
+      />
+    </div>
+  )
+}
+
+export default JumpToTopButton