Bug412-JiangLetian

1. Add jquery.js and word_operation.js to the static folder.

2. Changed the return type of the familiar, unfamiliar and deleteword methods of user_service.py.
    ```
    original: return redirect(url_for('userpage', username=username))
    now: return "success"
    ```
3. In order to get elements in JS to make ajax requests we add ids in userpage_get.html for familiar, unfamiliar, delete buttons and so on.

4. When the user's word book was retrieved, the list returned was already sorted in descending order of frequency, so redundant code was removed in userpage_get.html.

Co-authored-by: PeterQiu <www.1392993990@qq.com>
Co-authored-by: Lan Hui <1348141770@qq.com>
Reviewed-on: http://121.4.94.30:3000/mrlan/EnglishPal/pulls/30
Co-authored-by: 邱忠辉 <1392993990@qq.com>
Co-committed-by: 邱忠辉 <1392993990@qq.com>

@@ -21,2 +26,3 @@
+//关闭正在读的单词
 function onReadClick(){
-    isRead = !isRead;
+    let isRead = !isRead;

@@ -19,0 +20,4 @@
+   //关闭当前正在读的单词
+   reader.cancel()
+   //创建新的朗读任务
+   let msg = new SpeechSynthesisUtterance(word);

@@ -10,1 +8,3 @@
-   var word = getWord();
+//填充字符
+function fillingWord(){
+   let word = getWord();

@@ -5,0 +1,4 @@
+var isRead = true;
+var isChoose = true;
+const reader = window.speechSynthesis; // 全局定义朗读者，以便朗读和暂停
+//获取字符

@@ -5,3 +5,2 @@
 function getWord(){
-   var word = window.getSelection?window.getSelection():document.selection.createRange().text;
-   return word;
+   return window.getSelection?window.getSelection():document.selection.createRange().text;

@@ -4,1 +1,3 @@
-
+var isRead = true;
+var isChoose = true;
+const reader = window.speechSynthesis; // 全局定义朗读者，以便朗读和暂停

@@ -11,3 +11,3 @@
    if (isRead) read(word);
    if (!isChoose) return;
-   var element = document.getElementById("selected-words");
+   let element = document.getElementById("selected-words");

@@ -19,0 +18,4 @@
+//@word 要朗读的单词
+function read(word){
+   //关闭当前正在读的单词
+   reader.cancel()

@@ -12,3 +12,3 @@
    if (!isChoose) return;
-   var element = document.getElementById("selected-words");
+   let element = document.getElementById("selected-words");
    element.value = element.value + " " + word;

@@ -19,0 +16,4 @@
+document.getElementById("text-content").addEventListener("click", fillingWord, false);
+//朗读单词
+//@word 要朗读的单词
+function read(word){